# Tableaux¶

AUTHORS:

• Mike Hansen (2007): initial version
• Jason Bandlow (2011): updated to use Parent/Element model, and many minor fixes
• Andrew Mathas (2012-13): completed the transition to the parent/element model begun by Jason Bandlow
• Travis Scrimshaw (11-22-2012): Added tuple options, changed *katabolism* to *catabolism*. Cleaned up documentation.
• Andrew Mathas (2016-08-11): Row standard tableaux added
• Oliver Pechenik (2018): Added increasing tableaux.

This file consists of the following major classes:

Element classes:

Factory classes:

Parent classes:

For display options, see Tableaux.options().

Todo

• Move methods that only apply to semistandard tableaux from tableau to semistandard tableau
• Copy/move functionality to skew tableaux
• Add a class for tableaux of a given shape (eg Tableaux_shape)
class sage.combinat.tableau.IncreasingTableau(parent, t, check=True)

A class to model an increasing tableau.

INPUT:

• t – a tableau, a list of iterables, or an empty list

An increasing tableau is a tableau whose entries are positive integers that are strictly increasing across rows and strictly increasing down columns.

EXAMPLES:

sage: t = IncreasingTableau([[1,2,3],[2,3]]); t
[[1, 2, 3], [2, 3]]
sage: t.shape()
[3, 2]
sage: t.pp() # pretty printing
1 2 3
2 3
sage: t = Tableau([[1,2],])
sage: s = IncreasingTableau(t); s
[[1, 2], ]
sage: IncreasingTableau([]) # The empty tableau
[]


You can also construct an IncreasingTableau from the appropriate Parent object:

sage: IT = IncreasingTableaux()
sage: IT([[1, 2, 3], [4, 5]])
[[1, 2, 3], [4, 5]]

K_bender_knuth(i)

Return the i-th K-Bender-Knuth operator (as defined in [DPS2017]) applied to self.

The $$i$$-th K-Bender-Knuth operator swaps the letters $$i$$ and $$i + 1$$ everywhere where doing so would not break increasingness.

EXAMPLES:

sage: T = IncreasingTableau([[1,3,4],[2,4,5]])
sage: T.K_bender_knuth(2)
[[1, 2, 4], [3, 4, 5]]
sage: T.K_bender_knuth(3)
[[1, 3, 4], [2, 4, 5]]

K_evacuation(ceiling=None)

Return the K-evacuation involution from [TY2009] to self.

EXAMPLES:

sage: T = IncreasingTableau([[1,3,4],[2,4,5]])
sage: T.K_evacuation()
[[1, 2, 4], [2, 3, 5]]
sage: T.K_evacuation(6)
[[2, 3, 5], [3, 4, 6]]
sage: U = IncreasingTableau([[1,3,4],[3,4,5],])
sage: U.K_evacuation()
[[1, 2, 3], [2, 3, 5], ]

K_promotion(ceiling=None)

Return the K-promotion operator from [Pec2014] applied to self.

EXAMPLES:

sage: T = IncreasingTableau([[1,3,4],[2,4,5]])
sage: T.K_promotion()
[[1, 2, 3], [3, 4, 5]]
sage: T.K_promotion(6)
[[1, 2, 3], [3, 4, 6]]
sage: U = IncreasingTableau([[1,3,4],[3,4,5],])
sage: U.K_promotion()
[[2, 3, 4], [3, 4, 5], ]

K_promotion_inverse(ceiling=None)

Return the inverse of K-promotion operator applied to self.

EXAMPLES:

sage: T = IncreasingTableau([[1,3,4],[2,4,5]])
sage: T.K_promotion_inverse()
[[1, 2, 4], [3, 4, 5]]
sage: T.K_promotion_inverse(6)
[[2, 4, 5], [3, 5, 6]]
sage: U = IncreasingTableau([[1,3,4],[3,4,5],])
sage: U.K_promotion_inverse()
[[1, 2, 4], [2, 4, 5], ]

check()

Check that self is a valid increasing tableau.

descent_set()

Compute the descents of the increasing tableau self as defined in [DPS2017].

The number $$i$$ is a descent of an increasing tableau if some instance of $$i + 1$$ appears in a lower row than some instance of $$i$$.

Note

This notion is close to the notion of descent for a standard tableau but is unrelated to the notion for semistandard tableaux.

EXAMPLES:

sage: T = IncreasingTableau([[1,2,4],[3,5,6]])
sage: T.descent_set()
[2, 4]
sage: U = IncreasingTableau([[1,3,4],[2,4,5]])
sage: U.descent_set()
[1, 3, 4]
sage: V = IncreasingTableau([[1,3,4],[3,4,5],[4,5]])
sage: V.descent_set()
[3, 4]

dual_K_evacuation(ceiling=None)

Return the dual K-evacuation involution applied to self.

EXAMPLES:

sage: T = IncreasingTableau([[1,3,4],[2,4,5]])
sage: T.dual_K_evacuation()
[[1, 2, 4], [2, 3, 5]]
sage: T.dual_K_evacuation(6)
[[2, 3, 5], [3, 4, 6]]
sage: U = IncreasingTableau([[1,3,4],[3,4,5],])
sage: U.dual_K_evacuation()
[[1, 2, 3], [2, 3, 5], ]

class sage.combinat.tableau.IncreasingTableaux(**kwds)

A factory class for the various classes of increasing tableaux.

An increasing tableau is a tableau whose entries are positive integers that are strictly increasing across rows and strictly increasing down columns. Note that Sage uses the English convention for partitions and tableaux; the longer rows are displayed on top.

INPUT:

Keyword arguments:

• size – the size of the tableaux
• shape – the shape of the tableaux
• eval – the weight (also called binary content) of the tableaux, where values can be either $$0$$ or $$1$$ with position $$i$$ being $$1$$ if and only if $$i$$ can appear in the tableaux
• max_entry – positive integer or infinity (oo); the maximum entry for the tableaux; if size or shape are specified, max_entry defaults to be size or the size of shape

Positional arguments:

• the first argument is interpreted as either size or shape according to whether it is an integer or a partition
• the second keyword argument will always be interpreted as eval

Warning

The eval is not the usual notion of eval or weight, where the $$i$$-th entry counts how many $$i$$’s appear in the tableau.

EXAMPLES:

sage: IT = IncreasingTableaux([2,1]); IT
Increasing tableaux of shape [2, 1] and maximum entry 3
sage: IT.list()
[[[1, 3], ], [[1, 2], ], [[1, 2], ], [[1, 3], ], [[2, 3], ]]

sage: IT = IncreasingTableaux(3); IT
Increasing tableaux of size 3 and maximum entry 3
sage: IT.list()
[[[1, 2, 3]],
[[1, 3], ],
[[1, 2], ],
[[1, 2], ],
[[1, 3], ],
[[2, 3], ],
[, , ]]

sage: IT = IncreasingTableaux(3, max_entry=2); IT
Increasing tableaux of size 3 and maximum entry 2
sage: IT.list()
[[[1, 2], ]]

sage: IT = IncreasingTableaux(3, max_entry=4); IT
Increasing tableaux of size 3 and maximum entry 4
sage: IT.list()
[[[1, 2, 3]],
[[1, 2, 4]],
[[1, 3, 4]],
[[2, 3, 4]],
[[1, 3], ],
[[1, 2], ],
[[1, 4], ],
[[1, 2], ],
[[1, 2], ],
[[1, 4], ],
[[1, 3], ],
[[1, 3], ],
[[1, 4], ],
[[2, 4], ],
[[2, 3], ],
[[2, 3], ],
[[2, 4], ],
[[3, 4], ],
[, , ],
[, , ],
[, , ],
[, , ]]

sage: IT = IncreasingTableaux(3, max_entry=oo); IT
Increasing tableaux of size 3
sage: IT
[[5, 7], ]

sage: IT = IncreasingTableaux(max_entry=2)
sage: list(IT)
[[], [], [], [[1, 2]], [, ]]
sage: IT
[, ]

sage: IncreasingTableaux()
[]

Element

alias of IncreasingTableau

class sage.combinat.tableau.IncreasingTableaux_all(max_entry=None)

All increasing tableaux.

EXAMPLES:

sage: T = IncreasingTableaux()
sage: T.cardinality()
+Infinity

sage: T = IncreasingTableaux(max_entry=3)
sage: list(T)
[[],
[],
[],
[],
[[1, 2]],
[[1, 3]],
[[2, 3]],
[, ],
[, ],
[, ],
[[1, 2, 3]],
[[1, 3], ],
[[1, 2], ],
[[1, 2], ],
[[1, 3], ],
[[2, 3], ],
[, , ]]

class sage.combinat.tableau.IncreasingTableaux_shape(p, max_entry=None)

Increasing tableaux of fixed shape $$p$$ with a given max entry.

An increasing tableau with max entry $$i$$ is required to have all its entries less or equal to $$i$$. It is not required to actually contain an entry $$i$$.

INPUT:

• p – a partition
• max_entry – the max entry; defaults to the size of p
class sage.combinat.tableau.IncreasingTableaux_shape_inf(p)

Increasing tableaux of fixed shape $$p$$ and no maximum entry.

class sage.combinat.tableau.IncreasingTableaux_shape_weight(p, wt)

Increasing tableaux of fixed shape $$p$$ and binary weight $$wt$$.

class sage.combinat.tableau.IncreasingTableaux_size(n, max_entry=None)

Increasing tableaux of fixed size $$n$$.

class sage.combinat.tableau.IncreasingTableaux_size_inf(n)

Increasing tableaux of fixed size $$n$$ with no maximum entry.

class sage.combinat.tableau.IncreasingTableaux_size_weight(n, wt)

Increasing tableaux of fixed size $$n$$ and weight $$wt$$.

class sage.combinat.tableau.RowStandardTableau(parent, t, check=True)

A class to model a row standard tableau.

A row standard tableau is a tableau whose entries are positive integers from 1 to $$m$$ that increase along rows.

INPUT:

• t – a Tableau, a list of iterables, or an empty list

EXAMPLES:

sage: t = RowStandardTableau([[3,4,5],[1,2]]); t
[[3, 4, 5], [1, 2]]
sage: t.shape()
[3, 2]
sage: t.pp() # pretty printing
3  4  5
1  2
sage: t.is_standard()
False
sage: RowStandardTableau([]) # The empty tableau
[]
sage: RowStandardTableau([[3,4,5],[1,2]]) in StandardTableaux()
False
sage: RowStandardTableau([[1,2,5],[3,4]]) in StandardTableaux()
True


When using code that will generate a lot of tableaux, it is more efficient to construct a RowStandardTableau from the appropriate Parent object:

sage: ST = RowStandardTableaux()
sage: ST([[3, 4, 5], [1, 2]])
[[3, 4, 5], [1, 2]]

check()

Check that self is a valid row standard tableau.

class sage.combinat.tableau.RowStandardTableaux

A factory for the various classes of row standard tableaux.

INPUT:

• either a non-negative integer (possibly specified with the keyword n) or a partition

OUTPUT:

• with no argument, the class of all standard tableaux
• with a non-negative integer argument, n, the class of all standard tableaux of size n
• with a partition argument, the class of all standard tableaux of that shape

A row standard tableau is a tableau that contains each of the entries from $$1$$ to $$n$$ exactly once and is increasing along rows.

All classes of row standard tableaux are iterable.

EXAMPLES:

sage: ST = RowStandardTableaux(3); ST
Row standard tableaux of size 3
sage: ST.first()
[[1, 2, 3]]
sage: ST.last()
[, , ]
sage: ST.cardinality()
10
sage: ST.list()
[[[1, 2, 3]],
[[2, 3], ],
[[1, 2], ],
[[1, 3], ],
[, , ],
[, , ],
[, , ],
[, , ],
[, , ],
[, , ]]

Element

alias of RowStandardTableau

class sage.combinat.tableau.RowStandardTableaux_all

All row standard tableaux.

class sage.combinat.tableau.RowStandardTableaux_shape(p)

Row Standard tableaux of a fixed shape $$p$$.

cardinality()

Return the number of row standard tableaux of this shape.

This is just the index of the corresponding Young subgroup in the full symmetric group.

EXAMPLES:

sage: RowStandardTableaux([3,2,1]).cardinality()
60
sage: RowStandardTableaux([2,2]).cardinality()
6
sage: RowStandardTableaux().cardinality()
1
sage: RowStandardTableaux([6,5,5,3]).cardinality()
1955457504
sage: RowStandardTableaux([]).cardinality()
1

class sage.combinat.tableau.RowStandardTableaux_size(n)

Row standard tableaux of fixed size $$n$$.

EXAMPLES:

sage: [ t for t in RowStandardTableaux(1) ]
[[]]
sage: [ t for t in RowStandardTableaux(2) ]
[[[1, 2]], [, ], [, ]]
sage: list(RowStandardTableaux(3))
[[[1, 2, 3]],
[[2, 3], ],
[[1, 2], ],
[[1, 3], ],
[, , ],
[, , ],
[, , ],
[, , ],
[, , ],
[, , ]]

an_element()

Returns a particular element of the class.

EXAMPLES:

sage: RowStandardTableaux(4).an_element()
[[1, 2, 3, 4]]

class sage.combinat.tableau.SemistandardTableau(parent, t, check=True)

A class to model a semistandard tableau.

INPUT:

• t – a tableau, a list of iterables, or an empty list

OUTPUT:

• A SemistandardTableau object constructed from t.

A semistandard tableau is a tableau whose entries are positive integers, which are weakly increasing in rows and strictly increasing down columns.

EXAMPLES:

sage: t = SemistandardTableau([[1,2,3],[2,3]]); t
[[1, 2, 3], [2, 3]]
sage: t.shape()
[3, 2]
sage: t.pp() # pretty printing
1 2 3
2 3
sage: t = Tableau([[1,2],])
sage: s = SemistandardTableau(t); s
[[1, 2], ]
sage: SemistandardTableau([]) # The empty tableau
[]


When using code that will generate a lot of tableaux, it is slightly more efficient to construct a SemistandardTableau from the appropriate Parent object:

sage: SST = SemistandardTableaux()
sage: SST([[1, 2, 3], [4, 5]])
[[1, 2, 3], [4, 5]]

check()

Check that self is a valid semistandard tableau.

class sage.combinat.tableau.SemistandardTableaux(**kwds)

A factory class for the various classes of semistandard tableaux.

INPUT:

Keyword arguments:

• size – The size of the tableaux
• shape – The shape of the tableaux
• eval – The weight (also called content or evaluation) of the tableaux
• max_entry – A maximum entry for the tableaux. This can be a positive integer or infinity (oo). If size or shape are specified, max_entry defaults to be size or the size of shape.

Positional arguments:

• The first argument is interpreted as either size or shape according to whether it is an integer or a partition
• The second keyword argument will always be interpreted as eval

OUTPUT:

• The appropriate class, after checking basic consistency tests. (For example, specifying eval implies a value for $$max_entry$$).

A semistandard tableau is a tableau whose entries are positive integers, which are weakly increasing in rows and strictly increasing down columns. Note that Sage uses the English convention for partitions and tableaux; the longer rows are displayed on top.

Classes of semistandard tableaux can be iterated over if and only if there is some restriction.

EXAMPLES:

sage: SST = SemistandardTableaux([2,1]); SST
Semistandard tableaux of shape [2, 1] and maximum entry 3
sage: SST.list()
[[[1, 1], ],
[[1, 1], ],
[[1, 2], ],
[[1, 2], ],
[[1, 3], ],
[[1, 3], ],
[[2, 2], ],
[[2, 3], ]]

sage: SST = SemistandardTableaux(3); SST
Semistandard tableaux of size 3 and maximum entry 3
sage: SST.list()
[[[1, 1, 1]],
[[1, 1, 2]],
[[1, 1, 3]],
[[1, 2, 2]],
[[1, 2, 3]],
[[1, 3, 3]],
[[2, 2, 2]],
[[2, 2, 3]],
[[2, 3, 3]],
[[3, 3, 3]],
[[1, 1], ],
[[1, 1], ],
[[1, 2], ],
[[1, 2], ],
[[1, 3], ],
[[1, 3], ],
[[2, 2], ],
[[2, 3], ],
[, , ]]

sage: SST = SemistandardTableaux(3, max_entry=2); SST
Semistandard tableaux of size 3 and maximum entry 2
sage: SST.list()
[[[1, 1, 1]],
[[1, 1, 2]],
[[1, 2, 2]],
[[2, 2, 2]],
[[1, 1], ],
[[1, 2], ]]

sage: SST = SemistandardTableaux(3, max_entry=oo); SST
Semistandard tableaux of size 3
sage: SST
[[3, 4], ]

sage: SemistandardTableaux(max_entry=2)
[[1, 1], ]

sage: SemistandardTableaux()
[]

Element

alias of SemistandardTableau

class sage.combinat.tableau.SemistandardTableaux_all(max_entry=None)

All semistandard tableaux.

list()
class sage.combinat.tableau.SemistandardTableaux_shape(p, max_entry=None)

Semistandard tableaux of fixed shape $$p$$ with a given max entry.

A semistandard tableau with max entry $$i$$ is required to have all its entries less or equal to $$i$$. It is not required to actually contain an entry $$i$$.

INPUT:

• p – a partition
• max_entry – the max entry; defaults to the size of p
cardinality(algorithm='hook')

Return the cardinality of self.

INPUT:

• algorithm – (default: 'hook') any one of the following:
• 'hook' – use Stanley’s hook length formula
• 'sum' – sum over the compositions of max_entry the number of semistandard tableau with shape and given weight vector

This is computed using Stanley’s hook length formula:

$f_{\lambda} = \prod_{u\in\lambda} \frac{n+c(u)}{h(u)}.$

where $$n$$ is the max_entry, $$c(u)$$ is the content of $$u$$, and $$h(u)$$ is the hook length of $$u$$. See [Sta-EC2] Corollary 7.21.4.

EXAMPLES:

sage: SemistandardTableaux([2,1]).cardinality()
8
sage: SemistandardTableaux([2,2,1]).cardinality()
75
sage: SymmetricFunctions(QQ).schur()([2,2,1]).expand(5)(1,1,1,1,1) # cross check
75
sage: SemistandardTableaux().cardinality()
126
sage: SemistandardTableaux([3,2,1]).cardinality()
896
sage: SemistandardTableaux([3,2,1], max_entry=7).cardinality()
2352
sage: SemistandardTableaux([6,5,4,3,2,1], max_entry=30).cardinality()
208361017592001331200
sage: ssts = [SemistandardTableaux(p, max_entry=6) for p in Partitions(5)]
sage: all(sst.cardinality() == sst.cardinality(algorithm='sum')
....:     for sst in ssts)
True

random_element()

Return a uniformly distributed random tableau of the given shape and max_entry.

Uses the algorithm from [Kra1999] based on the Novelli-Pak-Stoyanovskii bijection

EXAMPLES:

http://www.sciencedirect.com/science/article/pii/0012365X9290368P
sage: SemistandardTableaux([2, 2, 1, 1]).random_element()
[[1, 1], [2, 3], , ]
sage: SemistandardTableaux([2, 2, 1, 1], max_entry=7).random_element()
[[1, 4], [5, 5], , ]

class sage.combinat.tableau.SemistandardTableaux_shape_inf(p)

Semistandard tableaux of fixed shape $$p$$ and no maximum entry.

class sage.combinat.tableau.SemistandardTableaux_shape_weight(p, mu)

Semistandard tableaux of fixed shape $$p$$ and weight $$\mu$$.

cardinality()

Returns the number of semistandard tableaux of the given shape and weight, as computed by kostka_number function of symmetrica.

EXAMPLES:

sage: SemistandardTableaux([2,2], [2, 1, 1]).cardinality()
1
sage: SemistandardTableaux([2,2,2], [2, 2, 1,1]).cardinality()
1
sage: SemistandardTableaux([2,2,2], [2, 2, 2]).cardinality()
1
sage: SemistandardTableaux([3,2,1], [2, 2, 2]).cardinality()
2

list()

Return a list of all semistandard tableaux in self generated by symmetrica.

EXAMPLES:

sage: SemistandardTableaux([2,2], [2, 1, 1]).list()
[[[1, 1], [2, 3]]]
sage: SemistandardTableaux([2,2,2], [2, 2, 1,1]).list()
[[[1, 1], [2, 2], [3, 4]]]
sage: SemistandardTableaux([2,2,2], [2, 2, 2]).list()
[[[1, 1], [2, 2], [3, 3]]]
sage: SemistandardTableaux([3,2,1], [2, 2, 2]).list()
[[[1, 1, 2], [2, 3], ], [[1, 1, 3], [2, 2], ]]

class sage.combinat.tableau.SemistandardTableaux_size(n, max_entry=None)

Semistandard tableaux of fixed size $$n$$.

cardinality()

Return the cardinality of self.

EXAMPLES:

sage: SemistandardTableaux(3).cardinality()
19
sage: SemistandardTableaux(4).cardinality()
116
sage: SemistandardTableaux(4, max_entry=2).cardinality()
9
sage: SemistandardTableaux(4, max_entry=10).cardinality()
4225
sage: ns = list(range(1, 6))
sage: ssts = [ SemistandardTableaux(n) for n in ns ]
sage: all(sst.cardinality() == len(sst.list()) for sst in ssts)
True

random_element()

Generate a random SemistandardTableau with uniform probability.

The RSK algorithm gives a bijection between symmetric $$k\times k$$ matrices of nonnegative integers that sum to $$n$$ and semistandard tableaux with size $$n$$ and maximum entry $$k$$.

The number of $$k\times k$$ symmetric matrices of nonnegative integers having sum of elements on the diagonal $$i$$ and sum of elements above the diagonal $$j$$ is $$\binom{k + i - 1}{k - 1}\binom{\binom{k}{2} + j - 1}{\binom{k}{2} - 1}$$. We first choose the sum of the elements on the diagonal randomly weighted by the number of matrices having that trace. We then create random integer vectors of length $$k$$ having that sum and use them to generate a $$k\times k$$ diagonal matrix. Then we take a random integer vector of length $$\binom{k}{2}$$ summing to half the remainder and distribute it symmetrically to the remainder of the matrix.

Applying RSK to the random symmetric matrix gives us a pair of identical SemistandardTableau of which we choose the first.

EXAMPLES:

sage: SemistandardTableaux(6).random_element() # random
[[1, 1, 2], [3, 5, 5]]
sage: SemistandardTableaux(6, max_entry=7).random_element() # random
[[2, 4, 4, 6, 6, 6]]

class sage.combinat.tableau.SemistandardTableaux_size_inf(n)

Semistandard tableaux of fixed size $$n$$ with no maximum entry.

list()
class sage.combinat.tableau.SemistandardTableaux_size_weight(n, mu)

Semistandard tableaux of fixed size $$n$$ and weight $$\mu$$.

cardinality()

Return the cardinality of self.

EXAMPLES:

sage: SemistandardTableaux(3, [2,1]).cardinality()
2
sage: SemistandardTableaux(4, [2,2]).cardinality()
3

class sage.combinat.tableau.StandardTableau(parent, t, check=True)

A class to model a standard tableau.

INPUT:

• t – a Tableau, a list of iterables, or an empty list

A standard tableau is a semistandard tableau whose entries are exactly the positive integers from 1 to $$n$$, where $$n$$ is the size of the tableau.

EXAMPLES:

sage: t = StandardTableau([[1,2,3],[4,5]]); t
[[1, 2, 3], [4, 5]]
sage: t.shape()
[3, 2]
sage: t.pp() # pretty printing
1 2 3
4 5
sage: t.is_standard()
True
sage: StandardTableau([]) # The empty tableau
[]
sage: StandardTableau([[1,2,3],[4,5]]) in RowStandardTableaux()
True


When using code that will generate a lot of tableaux, it is more efficient to construct a StandardTableau from the appropriate Parent object:

sage: ST = StandardTableaux()
sage: ST([[1, 2, 3], [4, 5]])
[[1, 2, 3], [4, 5]]

check()

Check that self is a standard tableau.

dominates(t)

Return True if self dominates the tableau t.

That is, if the shape of the tableau restricted to $$k$$ dominates the shape of t restricted to $$k$$, for $$k = 1, 2, \ldots, n$$.

When the two tableaux have the same shape, then this ordering coincides with the Bruhat ordering for the corresponding permutations.

INPUT:

• t – a tableau

EXAMPLES:

sage: s=StandardTableau([[1,2,3],[4,5]])
sage: t=StandardTableau([[1,2],[3,5],])
sage: s.dominates(t)
True
sage: t.dominates(s)
False
sage: all(StandardTableau(s).dominates(t) for t in StandardTableaux([3,2]))
True
sage: s.dominates([[1,2,3,4,5]])
False

down()

An iterator for all the standard tableaux that can be obtained from self by removing a cell. Note that this iterates just over a single tableau (or nothing if self is empty).

EXAMPLES:

sage: t = StandardTableau([[1,2],])
sage: [x for x in t.down()]
[[[1, 2]]]
sage: t = StandardTableau([])
sage: [x for x in t.down()]
[]

down_list()

Return a list of all the standard tableaux that can be obtained from self by removing a cell. Note that this is just a singleton list if self is nonempty, and an empty list otherwise.

EXAMPLES:

sage: t = StandardTableau([[1,2],])
sage: t.down_list()
[[[1, 2]]]
sage: t = StandardTableau([])
sage: t.down_list()
[]

is_standard()

Return True since self is a standard tableau.

EXAMPLES:

sage: StandardTableau([[1, 3], [2, 4]]).is_standard()
True

promotion(n=None)

Return the image of self under the promotion operator.

The promotion operator, applied to a standard tableau $$t$$, does the following:

Remove the letter $$n$$ from $$t$$, thus leaving a hole where it used to be. Apply jeu de taquin to move this hole southwest (in French notation) until it reaches the inner boundary of $$t$$. Fill $$0$$ into the hole once jeu de taquin has completed. Finally, add $$1$$ to each letter in the tableau. The resulting standard tableau is the image of $$t$$ under the promotion operator.

This definition of promotion is precisely the one given in [Hai1992] (p. 90). It is the inverse of the maps called “promotion” in [Sag2011] (p. 23) and in [Stan2009].

See the promotion() method for a more general operator.

EXAMPLES:

sage: ST = StandardTableaux(7)
sage: all( st.promotion().promotion_inverse() == st for st in ST ) # long time
True
sage: all( st.promotion_inverse().promotion() == st for st in ST ) # long time
True
sage: st = StandardTableau([[1,2,5],[3,4]])
sage: parent(st.promotion())
Standard tableaux

promotion_inverse(n=None)

Return the image of self under the inverse promotion operator. The optional variable $$m$$ should be set to the size of self minus $$1$$ for a minimal speedup; otherwise, it defaults to this number.

The inverse promotion operator, applied to a standard tableau $$t$$, does the following:

Remove the letter $$1$$ from $$t$$, thus leaving a hole where it used to be. Apply jeu de taquin to move this hole northeast (in French notation) until it reaches the outer boundary of $$t$$. Fill $$n + 1$$ into this hole, where $$n$$ is the size of $$t$$. Finally, subtract $$1$$ from each letter in the tableau. This yields a new standard tableau.

This definition of inverse promotion is the map called “promotion” in [Sag2011] (p. 23) and in [Stan2009], and is the inverse of the map called “promotion” in [Hai1992] (p. 90).

See the promotion_inverse() method for a more general operator.

EXAMPLES:

sage: t = StandardTableau([[1,3],[2,4]])
sage: t.promotion_inverse()
[[1, 2], [3, 4]]


We check the equivalence of two definitions of inverse promotion on standard tableaux:

sage: ST = StandardTableaux(7)
sage: def bk_promotion_inverse7(st):
....:     st2 = st
....:     for i in range(1, 7):
....:         st2 = st2.bender_knuth_involution(i, check=False)
....:     return st2
sage: all( bk_promotion_inverse7(st) == st.promotion_inverse() for st in ST ) # long time
True

standard_descents()

Return a list of the integers $$i$$ such that $$i$$ appears strictly further north than $$i + 1$$ in self (this is not to say that $$i$$ and $$i + 1$$ must be in the same column). The list is sorted in increasing order.

EXAMPLES:

sage: StandardTableau( [[1,3,4],[2,5]] ).standard_descents()
[1, 4]
sage: StandardTableau( [[1,2],[3,4]] ).standard_descents()

sage: StandardTableau( [[1,2,5],[3,4],[6,7],,] ).standard_descents()
[2, 5, 7, 8]
sage: StandardTableau( [] ).standard_descents()
[]

standard_major_index()

Return the major index of the standard tableau self in the standard meaning of the word. The major index is defined to be the sum of the descents of self (see standard_descents() for their definition).

EXAMPLES:

sage: StandardTableau( [[1,4,5],[2,6],] ).standard_major_index()
8
sage: StandardTableau( [[1,2],[3,4]] ).standard_major_index()
2
sage: StandardTableau( [[1,2,3],[4,5]] ).standard_major_index()
3

standard_number_of_descents()

Return the number of all integers $$i$$ such that $$i$$ appears strictly further north than $$i + 1$$ in self (this is not to say that $$i$$ and $$i + 1$$ must be in the same column). A list of these integers can be obtained using the standard_descents() method.

EXAMPLES:

sage: StandardTableau( [[1,2],[3,4],] ).standard_number_of_descents()
2
sage: StandardTableau( [] ).standard_number_of_descents()
0
sage: tabs = StandardTableaux(5)
sage: all( t.standard_number_of_descents() == t.schuetzenberger_involution().standard_number_of_descents() for t in tabs )
True

up()

An iterator for all the standard tableaux that can be obtained from self by adding a cell.

EXAMPLES:

sage: t = StandardTableau([[1,2]])
sage: [x for x in t.up()]
[[[1, 2, 3]], [[1, 2], ]]

up_list()

Return a list of all the standard tableaux that can be obtained from self by adding a cell.

EXAMPLES:

sage: t = StandardTableau([[1,2]])
sage: t.up_list()
[[[1, 2, 3]], [[1, 2], ]]

class sage.combinat.tableau.StandardTableaux(**kwds)

A factory for the various classes of standard tableaux.

INPUT:

• Either a non-negative integer (possibly specified with the keyword n) or a partition.

OUTPUT:

• With no argument, the class of all standard tableaux
• With a non-negative integer argument, n, the class of all standard tableaux of size n
• With a partition argument, the class of all standard tableaux of that shape.

A standard tableau is a semistandard tableaux which contains each of the entries from 1 to n exactly once.

All classes of standard tableaux are iterable.

EXAMPLES:

sage: ST = StandardTableaux(3); ST
Standard tableaux of size 3
sage: ST.first()
[[1, 2, 3]]
sage: ST.last()
[, , ]
sage: ST.cardinality()
4
sage: ST.list()
[[[1, 2, 3]], [[1, 3], ], [[1, 2], ], [, , ]]

Element

alias of StandardTableau

class sage.combinat.tableau.StandardTableaux_all

All standard tableaux.

class sage.combinat.tableau.StandardTableaux_shape(p)

Semistandard tableaux of a fixed shape $$p$$.

cardinality()

Return the number of standard Young tableaux of this shape.

This method uses the so-called hook length formula, a formula for the number of Young tableaux associated with a given partition. The formula says the following: Let $$\lambda$$ be a partition. For each cell $$c$$ of the Young diagram of $$\lambda$$, let the hook length of $$c$$ be defined as $$1$$ plus the number of cells horizontally to the right of $$c$$ plus the number of cells vertically below $$c$$. The number of standard Young tableaux of shape $$\lambda$$ is then $$n!$$ divided by the product of the hook lengths of the shape of $$\lambda$$, where $$n = |\lambda|$$.

For example, consider the partition [3,2,1] of 6 with Ferrers diagram:

# # #
# #
#


When we fill in the cells with their respective hook lengths, we obtain:

5 3 1
3 1
1


The hook length formula returns

$\frac{6!}{5 \cdot 3 \cdot 1 \cdot 3 \cdot 1 \cdot 1} = 16.$

EXAMPLES:

sage: StandardTableaux([3,2,1]).cardinality()
16
sage: StandardTableaux([2,2]).cardinality()
2
sage: StandardTableaux().cardinality()
1
sage: StandardTableaux([6,5,5,3]).cardinality()
6651216
sage: StandardTableaux([]).cardinality()
1


REFERENCES:

list()

Return a list of the standard Young tableaux of the specified shape.

EXAMPLES:

sage: StandardTableaux([2,2]).list()
[[[1, 3], [2, 4]], [[1, 2], [3, 4]]]
sage: StandardTableaux().list()
[[[1, 2, 3, 4, 5]]]
sage: StandardTableaux([3,2,1]).list()
[[[1, 4, 6], [2, 5], ],
[[1, 3, 6], [2, 5], ],
[[1, 2, 6], [3, 5], ],
[[1, 3, 6], [2, 4], ],
[[1, 2, 6], [3, 4], ],
[[1, 4, 5], [2, 6], ],
[[1, 3, 5], [2, 6], ],
[[1, 2, 5], [3, 6], ],
[[1, 3, 4], [2, 6], ],
[[1, 2, 4], [3, 6], ],
[[1, 2, 3], [4, 6], ],
[[1, 3, 5], [2, 4], ],
[[1, 2, 5], [3, 4], ],
[[1, 3, 4], [2, 5], ],
[[1, 2, 4], [3, 5], ],
[[1, 2, 3], [4, 5], ]]

random_element()

Return a random standard tableau of the given shape using the Greene-Nijenhuis-Wilf Algorithm.

EXAMPLES:

sage: StandardTableaux([2,2]).random_element()
[[1, 2], [3, 4]]
sage: StandardTableaux([]).random_element()
[]

class sage.combinat.tableau.StandardTableaux_size(n)

Standard tableaux of fixed size $$n$$.

EXAMPLES:

sage: [ t for t in StandardTableaux(1) ]
[[]]
sage: [ t for t in StandardTableaux(2) ]
[[[1, 2]], [, ]]
sage: [ t for t in StandardTableaux(3) ]
[[[1, 2, 3]], [[1, 3], ], [[1, 2], ], [, , ]]
sage: StandardTableaux(4)[:]
[[[1, 2, 3, 4]],
[[1, 3, 4], ],
[[1, 2, 4], ],
[[1, 2, 3], ],
[[1, 3], [2, 4]],
[[1, 2], [3, 4]],
[[1, 4], , ],
[[1, 3], , ],
[[1, 2], , ],
[, , , ]]

cardinality()

Return the number of all standard tableaux of size n.

The number of standard tableaux of size $$n$$ is equal to the number of involutions in the symmetric group $$S_n$$. This is a consequence of the symmetry of the RSK correspondence, that if $$\sigma \mapsto (P, Q)$$, then $$\sigma^{-1} \mapsto (Q, P)$$. For more information, see Wikipedia article Robinson-Schensted-Knuth_correspondence#Symmetry.

ALGORITHM:

The algorithm uses the fact that standard tableaux of size n are in bijection with the involutions of size n, (see page 41 in section 4.1 of [Ful1997]). For each number of fixed points, you count the number of ways to choose those fixed points multiplied by the number of perfect matchings on the remaining values.

EXAMPLES:

sage: StandardTableaux(3).cardinality()
4
sage: ns = [1,2,3,4,5,6]
sage: sts = [StandardTableaux(n) for n in ns]
sage: all(st.cardinality() == len(st.list()) for st in sts)
True


The cardinality can be computed without constructing all elements in this set, so this computation is fast (see also trac ticket #28273):

sage: StandardTableaux(500).cardinality()
423107565308608549951551753690...221285999236657443927937253376

random_element()

Return a random StandardTableau with uniform probability.

This algorithm uses the fact that the Robinson-Schensted correspondence returns a pair of identical standard Young tableaux (SYTs) if and only if the permutation was an involution. Thus, generating a random SYT is equivalent to generating a random involution.

To generate an involution, we first need to choose its number of fixed points $$k$$ (if the size of the involution is even, the number of fixed points will be even, and if the size is odd, the number of fixed points will be odd). To do this, we choose a random integer $$r$$ between 0 and the number $$N$$ of all involutions of size $$n$$. We then decompose the interval $$\{ 1, 2, \ldots, N \}$$ into subintervals whose lengths are the numbers of involutions of size $$n$$ with respectively $$0$$, $$1$$, $$\ldots$$, $$\left \lfloor N/2 \right \rfloor$$ fixed points. The interval in which our random integer $$r$$ lies then decides how many fixed points our random involution will have. We then place those fixed points randomly and then compute a perfect matching (an involution without fixed points) on the remaining values.

EXAMPLES:

sage: StandardTableaux(10).random_element() # random
[[1, 3, 6], [2, 5, 7], [4, 8], , ]
sage: StandardTableaux(0).random_element()
[]
sage: StandardTableaux(1).random_element()
[]

class sage.combinat.tableau.Tableau(parent, t, check=True)

A class to model a tableau.

INPUT:

• t – a Tableau, a list of iterables, or an empty list

OUTPUT:

• A Tableau object constructed from t.

A tableau is abstractly a mapping from the cells in a partition to arbitrary objects (called entries). It is often represented as a finite list of nonempty lists (or, more generally an iterator of iterables) of weakly decreasing lengths. This list, in particular, can be empty, representing the empty tableau.

Note that Sage uses the English convention for partitions and tableaux; the longer rows are displayed on top.

EXAMPLES:

sage: t = Tableau([[1,2,3],[4,5]]); t
[[1, 2, 3], [4, 5]]
sage: t.shape()
[3, 2]
sage: t.pp() # pretty printing
1 2 3
4 5
sage: t.is_standard()
True

sage: Tableau([['a','c','b'],[[],(2,1)]])
[['a', 'c', 'b'], [[], (2, 1)]]
sage: Tableau([]) # The empty tableau
[]


When using code that will generate a lot of tableaux, it is slightly more efficient to construct a Tableau from the appropriate Parent object:

sage: T = Tableaux()
sage: T([[1, 2, 3], [4, 5]])
[[1, 2, 3], [4, 5]]

add_entry(cell, m)

Return the result of setting the entry in cell cell equal to m in the tableau self.

This tableau has larger size than self if cell does not belong to the shape of self; otherwise, the tableau has the same shape as self and has the appropriate entry replaced.

INPUT:

• cell – a pair of nonnegative integers

OUTPUT:

The tableau self with the entry in cell cell set to m. This entry overwrites an existing entry if cell already belongs to self, or is added to the tableau if cell is a cocorner of the shape self. (Either way, the input is not modified.)

Note

Both coordinates of cell are interpreted as starting at $$0$$. So, cell == (0, 0) corresponds to the northwesternmost cell.

EXAMPLES:

sage: s = StandardTableau([[1,2,5],[3,4]]); s.pp()
1  2  5
3  4
sage: t = s.add_entry( (1,2), 6); t.pp()
1  2  5
3  4  6
sage: t.category()
Category of elements of Standard tableaux
1  2  5
3  4
6
sage: u = s.add_entry( (1,2), 3); u.pp()
1  2  5
3  4  3
sage: u.category()
Category of elements of Tableaux
Traceback (most recent call last):
...
IndexError: (2, 2) is not an addable cell of the tableau

anti_restrict(n)

Return the skew tableau formed by removing all of the cells from self that are filled with a number at most $$n$$.

EXAMPLES:

sage: t = Tableau([[1,2,3],[4,5]]); t
[[1, 2, 3], [4, 5]]
sage: t.anti_restrict(1)
[[None, 2, 3], [4, 5]]
sage: t.anti_restrict(2)
[[None, None, 3], [4, 5]]
sage: t.anti_restrict(3)
[[None, None, None], [4, 5]]
sage: t.anti_restrict(4)
[[None, None, None], [None, 5]]
sage: t.anti_restrict(5)
[[None, None, None], [None, None]]

atom()

EXAMPLES:

sage: Tableau([[1,2],[3,4]]).atom()
[2, 2]
sage: Tableau([[1,2,3],[4,5],]).atom()
[3, 2, 1]

bender_knuth_involution(k, rows=None, check=True)

Return the image of self under the $$k$$-th Bender–Knuth involution, assuming self is a semistandard tableau.

Let $$T$$ be a tableau, then a lower free k in T means a cell of $$T$$ which is filled with the integer $$k$$ and whose direct lower neighbor is not filled with the integer $$k + 1$$ (in particular, this lower neighbor might not exist at all). Let an upper free k + 1 in T mean a cell of $$T$$ which is filled with the integer $$k + 1$$ and whose direct upper neighbor is not filled with the integer $$k$$ (in particular, this neighbor might not exist at all). It is clear that for any row $$r$$ of $$T$$, the lower free $$k$$’s and the upper free $$k + 1$$’s in $$r$$ together form a contiguous interval or $$r$$.

The k-th Bender–Knuth switch at row i changes the entries of the cells in this interval in such a way that if it used to have $$a$$ entries of $$k$$ and $$b$$ entries of $$k + 1$$, it will now have $$b$$ entries of $$k$$ and $$a$$ entries of $$k + 1$$. For fixed $$k$$, the $$k$$-th Bender–Knuth switches for different $$i$$ commute. The composition of the $$k$$-th Bender–Knuth switches for all rows is called the k-th Bender-Knuth involution. This is used to show that the Schur functions defined by semistandard tableaux are symmetric functions.

INPUT:

• k – an integer
• rows – (Default None) When set to None, the method computes the $$k$$-th Bender–Knuth involution as defined above. When an iterable, this computes the composition of the $$k$$-th Bender–Knuth switches at row $$i$$ over all $$i$$ in rows. When set to an integer $$i$$, the method computes the $$k$$-th Bender–Knuth switch at row $$i$$. Note the indexing of the rows starts with $$1$$.
• check – (Default: True) Check to make sure self is semistandard. Set to False to avoid this check.

OUTPUT:

The image of self under either the $$k$$-th Bender–Knuth involution, the $$k$$-th Bender–Knuth switch at a certain row, or the composition of such switches, as detailed in the INPUT section.

EXAMPLES:

sage: t = Tableau([[1,1,3,4,4,5,6,7],[2,2,4,6,7,7,7],[3,4,5,8,8,9],[6,6,7,10],[7,8,8,11],])
sage: t.bender_knuth_involution(1) == t
True
sage: t.bender_knuth_involution(2)
[[1, 1, 2, 4, 4, 5, 6, 7], [2, 3, 4, 6, 7, 7, 7], [3, 4, 5, 8, 8, 9], [6, 6, 7, 10], [7, 8, 8, 11], ]
sage: t.bender_knuth_involution(3)
[[1, 1, 3, 3, 3, 5, 6, 7], [2, 2, 4, 6, 7, 7, 7], [3, 4, 5, 8, 8, 9], [6, 6, 7, 10], [7, 8, 8, 11], ]
sage: t.bender_knuth_involution(4)
[[1, 1, 3, 4, 5, 5, 6, 7], [2, 2, 4, 6, 7, 7, 7], [3, 5, 5, 8, 8, 9], [6, 6, 7, 10], [7, 8, 8, 11], ]
sage: t.bender_knuth_involution(5)
[[1, 1, 3, 4, 4, 5, 6, 7], [2, 2, 4, 5, 7, 7, 7], [3, 4, 6, 8, 8, 9], [5, 5, 7, 10], [7, 8, 8, 11], ]
sage: t.bender_knuth_involution(666) == t
True
sage: t.bender_knuth_involution(4, 2) == t
True
sage: t.bender_knuth_involution(4, 3)
[[1, 1, 3, 4, 4, 5, 6, 7], [2, 2, 4, 6, 7, 7, 7], [3, 5, 5, 8, 8, 9], [6, 6, 7, 10], [7, 8, 8, 11], ]


The rows keyword can be an iterator:

sage: t.bender_knuth_involution(6, iter([1,2])) == t
False
sage: t.bender_knuth_involution(6, iter([3,4])) == t
True


The Bender–Knuth involution is an involution:

sage: T = SemistandardTableaux(shape=[3,1,1], max_entry=4)
sage: all(all(t.bender_knuth_involution(k).bender_knuth_involution(k) == t for k in range(1,5)) for t in T)
True


The same holds for the single switches:

sage: all(all(t.bender_knuth_involution(k, j).bender_knuth_involution(k, j) == t for k in range(1,5) for j in range(1, 5)) for t in T)
True


Locality of the Bender–Knuth involutions:

sage: all(all(t.bender_knuth_involution(k).bender_knuth_involution(l) == t.bender_knuth_involution(l).bender_knuth_involution(k) for k in range(1,5) for l in range(1,5) if abs(k - l) > 1) for t in T)
True


Berenstein and Kirillov [KB1995] have shown that $$(s_1 s_2)^6 = id$$ (for tableaux of straight shape):

sage: p = lambda t, k: t.bender_knuth_involution(k).bender_knuth_involution(k + 1)
sage: all(p(p(p(p(p(p(t,1),1),1),1),1),1) == t for t in T)
True


However, $$(s_2 s_3)^6 = id$$ is false:

sage: p = lambda t, k: t.bender_knuth_involution(k).bender_knuth_involution(k + 1)
sage: t = Tableau([[1,2,2],[3,4]])
sage: x = t
sage: for i in range(6): x = p(x, 2)
sage: x
[[1, 2, 3], [2, 4]]
sage: x == t
False

bump(x)

Insert x into self using Schensted’s row-bumping (or row-insertion) algorithm.

EXAMPLES:

sage: t = Tableau([[1,2],])
sage: t.bump(1)
[[1, 1], , ]
sage: t
[[1, 2], ]
sage: t.bump(2)
[[1, 2, 2], ]
sage: t.bump(3)
[[1, 2, 3], ]
sage: t
[[1, 2], ]
sage: t = Tableau([[1,2,2,3],[2,3,5,5],[4,4,6],[5,6]])
sage: t.bump(2)
[[1, 2, 2, 2], [2, 3, 3, 5], [4, 4, 5], [5, 6, 6]]
sage: t.bump(1)
[[1, 1, 2, 3], [2, 2, 5, 5], [3, 4, 6], [4, 6], ]

bump_multiply(left, right)

Multiply two tableaux using Schensted’s bump.

This product makes the set of semistandard tableaux into an associative monoid. The empty tableau is the unit in this monoid. See pp. 11-12 of [Ful1997].

The same product operation is implemented in a different way in slide_multiply().

EXAMPLES:

sage: t = Tableau([[1,2,2,3],[2,3,5,5],[4,4,6],[5,6]])
sage: t2 = Tableau([[1,2],])
sage: t.bump_multiply(t2)
[[1, 1, 2, 2, 3], [2, 2, 3, 5], [3, 4, 5], [4, 6, 6], ]

catabolism()

Remove the top row of self and insert it back in using column Schensted insertion (starting with the largest letter).

EXAMPLES:

sage: Tableau([]).catabolism()
[]
sage: Tableau([[1,2,3,4,5]]).catabolism()
[[1, 2, 3, 4, 5]]
sage: Tableau([[1,1,3,3],[2,3],]).catabolism()
[[1, 1, 2, 3, 3, 3], ]
sage: Tableau([[1, 1, 2, 3, 3, 3], ]).catabolism()
[[1, 1, 2, 3, 3, 3, 3]]

catabolism_projector(parts)

EXAMPLES:

sage: t = Tableau([[1,1,3,3],[2,3],])
sage: t.catabolism_projector([[4,2,1]])
[[1, 1, 3, 3], [2, 3], ]
sage: t.catabolism_projector([])
[]
sage: t.catabolism_projector([[2,1],])
[]
sage: t.catabolism_projector([[1,1],[4,1]])
[[1, 1, 3, 3], [2, 3], ]

catabolism_sequence()

Perform catabolism() on self until it returns a tableau consisting of a single row.

EXAMPLES:

sage: t = Tableau([[1,2,3,4,5,6,8],[7,9]])
sage: t.catabolism_sequence()
[[[1, 2, 3, 4, 5, 6, 8], [7, 9]],
[[1, 2, 3, 4, 5, 6, 7, 9], ],
[[1, 2, 3, 4, 5, 6, 7, 8], ],
[[1, 2, 3, 4, 5, 6, 7, 8, 9]]]
sage: Tableau([]).catabolism_sequence()
[[]]

cells()

Return a list of the coordinates of the cells of self.

Coordinates start at $$0$$, so the northwesternmost cell (in English notation) has coordinates $$(0, 0)$$.

EXAMPLES:

sage: Tableau([[1,2],[3,4]]).cells()
[(0, 0), (0, 1), (1, 0), (1, 1)]

cells_containing(i)

Return the list of cells in which the letter $$i$$ appears in the tableau self. The list is ordered with cells appearing from left to right.

Cells are given as pairs of coordinates $$(a, b)$$, where both rows and columns are counted from $$0$$ (so $$a = 0$$ means the cell lies in the leftmost column of the tableau, etc.).

EXAMPLES:

sage: t = Tableau([[1,1,3],[2,3,5],[4,5]])
sage: t.cells_containing(5)
[(2, 1), (1, 2)]
sage: t.cells_containing(4)
[(2, 0)]
sage: t.cells_containing(6)
[]

sage: t = Tableau([[1,1,2,4],[2,4,4],])
sage: t.cells_containing(4)
[(2, 0), (1, 1), (1, 2), (0, 3)]

sage: t = Tableau([[1,1,2,8,9],[2,5,6,11],[3,7,7,13],[4,8,9],,,])
sage: t.cells_containing(8)
[(3, 1), (0, 3)]

sage: Tableau([]).cells_containing(3)
[]

charge()

Return the charge of the reading word of self. See charge() for more information.

EXAMPLES:

sage: Tableau([[1,1],[2,2],]).charge()
0
sage: Tableau([[1,1,3],[2,2]]).charge()
1
sage: Tableau([[1,1,2],,]).charge()
1
sage: Tableau([[1,1,2],[2,3]]).charge()
2
sage: Tableau([[1,1,2,3],]).charge()
2
sage: Tableau([[1,1,2,2],]).charge()
3
sage: Tableau([[1,1,2,2,3]]).charge()
4

check()

Check that self is a valid straight-shape tableau.

EXAMPLES:

sage: t = Tableau([[1,1],])
sage: t.check()

sage: t = Tableau([[None, None, 1], [2, 4], [3, 4, 5]])  # indirect doctest
Traceback (most recent call last):
...
ValueError: A tableau must be a list of iterables of weakly decreasing length.

cocharge()

Return the cocharge of the reading word of self. See cocharge() for more information.

EXAMPLES:

sage: Tableau([[1,1],[2,2],]).cocharge()
4
sage: Tableau([[1,1,3],[2,2]]).cocharge()
3
sage: Tableau([[1,1,2],,]).cocharge()
3
sage: Tableau([[1,1,2],[2,3]]).cocharge()
2
sage: Tableau([[1,1,2,3],]).cocharge()
2
sage: Tableau([[1,1,2,2],]).cocharge()
1
sage: Tableau([[1,1,2,2,3]]).cocharge()
0

codegree(e, multicharge=(0, ))

Return the Brundan-Kleshchev-Wang [BKW2011] codegree of the standard tableau self.

The codegree of a tableau is an integer that is defined recursively by successively stripping off the number $$k$$, for $$k = n, n-1, \ldots, 1$$ and at stage adding the number of addable cell of the same residue minus the number of removable cells of the same residue as $$k$$ and are above $$k$$ in the diagram.

The codegree of the tableau $$T$$ gives the degree of “dual” homogeneous basis element of the Graded Specht module that is indexed by $$T$$.

INPUT:

• e – the quantum characteristic
• multicharge – (default: ) the multicharge

OUTPUT:

The codegree of the tableau self, which is an integer.

EXAMPLES:

sage: StandardTableau([[1,3,5],[2,4]]).codegree(3)
0
sage: StandardTableau([[1,2,5],[3,4]]).codegree(3)
1
sage: StandardTableau([[1,2,5],[3,4]]).codegree(4)
0

column_stabilizer()

Return the PermutationGroup corresponding to the column stabilizer of self.

This assumes that every integer from $$1$$ to the size of self appears exactly once in self.

EXAMPLES:

sage: cs = Tableau([[1,2,3],[4,5]]).column_stabilizer()
sage: cs.order() == factorial(2)*factorial(2)
True
sage: PermutationGroupElement([(1,3,2),(4,5)]) in cs
False
sage: PermutationGroupElement([(1,4)]) in cs
True

components()

This function returns a list containing itself. It exists mainly for compatibility with TableauTuple as it allows constructions like the example below.

EXAMPLES:

sage: t = Tableau([[1,2,3],[4,5]])
sage: for s in t.components(): print(s.to_list())
[[1, 2, 3], [4, 5]]

conjugate()

Return the conjugate of self.

EXAMPLES:

sage: Tableau([[1,2],[3,4]]).conjugate()
[[1, 3], [2, 4]]
sage: c = StandardTableau([[1,2],[3,4]]).conjugate()
sage: c.parent()
Standard tableaux

content(k, multicharge=)

Return the content of k in the standard tableau self.

The content of $$k$$ is $$c - r$$ if $$k$$ appears in row $$r$$ and column $$c$$ of the tableau.

The multicharge is a list of length 1 which gives an offset for all of the contents. It is included mainly for compatibility with sage.combinat.tableau_tuple.TableauTuple().

EXAMPLES:

sage: StandardTableau([[1,2],[3,4]]).content(3)
-1

sage: StandardTableau([[1,2],[3,4]]).content(6)
Traceback (most recent call last):
...
ValueError: 6 does not appear in tableau

corners()

Return the corners of the tableau self.

EXAMPLES:

sage: Tableau([[1, 4, 6], [2, 5], ]).corners()
[(0, 2), (1, 1), (2, 0)]
sage: Tableau([[1, 3], [2, 4]]).corners()
[(1, 1)]

degree(e, multicharge=(0, ))

Return the Brundan-Kleshchev-Wang [BKW2011] degree of self.

The degree is an integer that is defined recursively by successively stripping off the number $$k$$, for $$k = n, n-1, \ldots, 1$$ and at stage adding the number of addable cell of the same residue minus the number of removable cells of the same residue as $$k$$ and which are below $$k$$ in the diagram.

The degrees of the tableau $$T$$ gives the degree of the homogeneous basis element of the graded Specht module that is indexed by $$T$$.

INPUT:

• e – the quantum characteristic
• multicharge – (default: ) the multicharge

OUTPUT:

The degree of the tableau self, which is an integer.

EXAMPLES:

sage: StandardTableau([[1,2,5],[3,4]]).degree(3)
0
sage: StandardTableau([[1,2,5],[3,4]]).degree(4)
1

descents()

Return a list of the cells (i,j) such that self[i][j] > self[i-1][j].

Warning

This is not to be confused with the descents of a standard tableau.

EXAMPLES:

sage: Tableau( [[1,4],[2,3]] ).descents()
[(1, 0)]
sage: Tableau( [[1,2],[3,4]] ).descents()
[(1, 0), (1, 1)]
sage: Tableau( [[1,2,3],[4,5]] ).descents()
[(1, 0), (1, 1)]

entries()

Return the tuple of all entries of self, in the order obtained by reading across the rows from top to bottom (in English notation).

EXAMPLES:

sage: t = Tableau([[1,3], ])
sage: t.entries()
(1, 3, 2)

entry(cell)

Returns the entry of cell cell in the tableau self. Here, cell should be given as a tuple $$(i,j)$$ of zero-based coordinates (so the northwesternmost cell in English notation is $$(0,0)$$).

EXAMPLES:

sage: t = Tableau([[1,2],[3,4]])
sage: t.entry( (0,0) )
1
sage: t.entry( (1,1) )
4

evacuation(n=None, check=True)

Return the evacuation of the tableau self.

This is an alias for schuetzenberger_involution().

This method relies on the analogous method on words, which reverts the word and then complements all letters within the underlying ordered alphabet. If $$n$$ is specified, the underlying alphabet is assumed to be $$[1, 2, \ldots, n]$$. If no alphabet is specified, $$n$$ is the maximal letter appearing in self.

INPUT:

• n – an integer specifying the maximal letter in the alphabet (optional)
• check – (Default: True) Check to make sure self is semistandard. Set to False to avoid this check. (optional)

OUTPUT:

• a tableau, the evacuation of self

EXAMPLES:

sage: t = Tableau([[1,1,1],[2,2]])
sage: t.evacuation(3)
[[2, 2, 3], [3, 3]]

sage: t = Tableau([[1,2,3],[4,5]])
sage: t.evacuation()
[[1, 2, 5], [3, 4]]

sage: t = Tableau([[1,3,5,7],[2,4,6],[8,9]])
sage: t.evacuation()
[[1, 2, 6, 8], [3, 4, 9], [5, 7]]

sage: t = Tableau([])
sage: t.evacuation()
[]

sage: t = StandardTableau([[1,2,3],[4,5]])
sage: s = t.evacuation()
sage: s.parent()
Standard tableaux

evaluation()

Return the weight of the tableau self. Trailing zeroes are omitted when returning the weight.

The weight of a tableau $$T$$ is the sequence $$(a_1, a_2, a_3, \ldots )$$, where $$a_k$$ is the number of entries of $$T$$ equal to $$k$$. This sequence contains only finitely many nonzero entries.

The weight of a tableau $$T$$ is the same as the weight of the reading word of $$T$$, for any reading order.

EXAMPLES:

sage: Tableau([[1,2],[3,4]]).weight()
[1, 1, 1, 1]

sage: Tableau([]).weight()
[]

sage: Tableau([[1,3,3,7],[4,2],[2,3]]).weight()
[1, 2, 3, 1, 0, 0, 1]

first_column_descent()

Return the first cell where self is not column standard.

Cells are ordered left to right along the rows and then top to bottom. That is, the cell $$(r, c)$$ with $$r$$ and $$c$$ minimal such that the entry in position $$(r, c)$$ is bigger than the entry in position $$(r, c+1)$$. If there is no such cell then None is returned - in this case the tableau is column strict.

OUTPUT:

The first cell which there is a descent or None if no such cell exists.

EXAMPLES:

sage: Tableau([[1,4,5],[2,3]]).first_column_descent()
(0, 1)
sage: Tableau([[1,2,3],]).first_column_descent() is None
True

first_row_descent()

Return the first cell where the tableau self is not row standard.

Cells are ordered left to right along the rows and then top to bottom. That is, the cell $$(r,c)$$ with $$r$$ and $$c$$ minimal such that the entry in position $$(r,c)$$ is bigger than the entry in position $$(r, c+1)$$. If there is no such cell then None is returned - in this case the tableau is row strict.

OUTPUT:

The first cell which there is a descent or None if no such cell exists.

EXAMPLES:

sage: t=Tableau([[1,3,2],]); t.first_row_descent()
(0, 1)
sage: Tableau([[1,2,3],]).first_row_descent() is  None
True

flush()

Return the number of flush segments in self, as in [Sal2014].

Let $$1 \le i < k \le r+1$$ and suppose $$\ell$$ is the smallest integer greater than $$k$$ such that there exists an $$\ell$$-segment in the $$(i+1)$$-st row of $$T$$. A $$k$$-segment in the $$i$$-th row of $$T$$ is called flush if the leftmost box in the $$k$$-segment and the leftmost box of the $$\ell$$-segment are in the same column of $$T$$. If, however, no such $$\ell$$ exists, then this $$k$$-segment is said to be flush if the number of boxes in the $$k$$-segment is equal to $$\theta_i$$, where $$\theta_i = \lambda_i - \lambda_{i+1}$$ and the shape of $$T$$ is $$\lambda = (\lambda_1 > \lambda_2 > \cdots > \lambda_r)$$. Denote the number of flush $$k$$-segments in $$T$$ by $$\mathrm{flush}(T)$$.

EXAMPLES:

sage: t = Tableau([[1,1,2,3,5],[2,3,5,5],[3,4]])
sage: t.flush()
3

sage: B = crystals.Tableaux("A4",shape=[4,3,2,1])
sage: t = B.to_tableau()
sage: t.flush()
4

height()

Return the height of self.

EXAMPLES:

sage: Tableau([[1,2,3],[4,5]]).height()
2
sage: Tableau([[1,2,3]]).height()
1
sage: Tableau([]).height()
0

hillman_grassl()

Return the image of the $$\lambda$$-array self under the Hillman-Grassl correspondence (as a WeakReversePlanePartition).

This relies on interpreting self as a $$\lambda$$-array in the sense of hillman_grassl.

Fix a partition $$\lambda$$ (see Partition()). We draw all partitions and tableaux in English notation.

A $$\lambda$$-array will mean a tableau of shape $$\lambda$$ whose entries are nonnegative integers. (No conditions on the order of these entries are made. Note that $$0$$ is allowed.)

A weak reverse plane partition of shape $$\lambda$$ (short: $$\lambda$$-rpp) will mean a $$\lambda$$-array whose entries weakly increase along each row and weakly increase along each column.

The Hillman-Grassl correspondence $$H$$ is the map that sends a $$\lambda$$-array $$M$$ to a $$\lambda$$-rpp $$H(M)$$ defined recursively as follows:

• If all entries of $$M$$ are $$0$$, then $$H(M) = M$$.
• Otherwise, let $$s$$ be the index of the leftmost column of $$M$$ containing a nonzero entry. Let $$r$$ be the index of the bottommost nonzero entry in the $$s$$-th column of $$M$$. Let $$M'$$ be the $$\lambda$$-array obtained from $$M$$ by subtracting $$1$$ from the $$(r, s)$$-th entry of $$M$$. Let $$Q = (q_{i, j})$$ be the image $$H(M')$$ (which is already defined by recursion).
• Define a sequence $$((i_1, j_1), (i_2, j_2), \ldots, (i_n, j_n))$$ of boxes in the diagram of $$\lambda$$ (actually a lattice path made of southward and westward steps) as follows: Set $$(i_1, j_1) = (r, \lambda_r)$$ (the rightmost box in the $$r$$-th row of $$\lambda$$). If $$(i_k, j_k)$$ is defined for some $$k \geq 1$$, then $$(i_{k+1}, j_{k+1})$$ is constructed as follows: If $$q_{i_k + 1, j_k}$$ is well-defined and equals $$q_{i_k, j_k}$$, then we set $$(i_{k+1}, j_{k+1}) = (i_k + 1, j_k)$$. Otherwise, if $$j_k = s$$, then the sequence ends here. Otherwise, we set $$(i_{k+1}, j_{k+1}) = (i_k, j_k - 1)$$.
• Let $$H(M)$$ be the array obtained from $$Q$$ by adding $$1$$ to the $$(i_k, j_k)$$-th entry of $$Q$$ for each $$k \in \{1, 2, \ldots, n\}$$.

See [Gans1981] (Section 3) for this construction.

hillman_grassl() for the Hillman-Grassl correspondence as a standalone function.

hillman_grassl_inverse() for the inverse map.

EXAMPLES:

sage: a = Tableau([[2, 1, 1], [0, 2, 0], [1, 1]])
sage: A = a.hillman_grassl(); A
[[2, 2, 4], [2, 3, 4], [3, 5]]
sage: A.parent(), a.parent()
(Weak Reverse Plane Partitions, Tableaux)

insert_word(w, left=False)

Insert the word w into the tableau self letter by letter using Schensted insertion. By default, the word w is being processed from left to right, and the insertion used is row insertion. If the optional keyword left is set to True, the word w is being processed from right to left, and column insertion is used instead.

EXAMPLES:

sage: t0 = Tableau([])
sage: w = [1,1,2,3,3,3,3]
sage: t0.insert_word(w)
[[1, 1, 2, 3, 3, 3, 3]]
sage: t0.insert_word(w,left=True)
[[1, 1, 2, 3, 3, 3, 3]]
sage: w.reverse()
sage: t0.insert_word(w)
[[1, 1, 3, 3], [2, 3], ]
sage: t0.insert_word(w,left=True)
[[1, 1, 3, 3], [2, 3], ]
sage: t1 = Tableau([[1,3],])
sage: t1.insert_word([4,5])
[[1, 3, 4, 5], ]
sage: t1.insert_word([4,5], left=True)
[[1, 3], [2, 5], ]

inversion_number()

Return the inversion number of self.

The inversion number is defined to be the number of inversions of self minus the sum of the arm lengths of the descents of self (see the inversions() and descents() methods for the relevant definitions).

Warning

This has none of the meanings in which the word “inversion” is used in the theory of standard tableaux.

EXAMPLES:

sage: t = Tableau([[1,2,3],[2,5]])
sage: t.inversion_number()
0
sage: t = Tableau([[1,2,4],[3,5]])
sage: t.inversion_number()
0

inversions()

Return a list of the inversions of self.

Let $$T$$ be a tableau. An inversion is an attacking pair $$(c,d)$$ of the shape of $$T$$ (see attacking_pairs() for a definition of this) such that the entry of $$c$$ in $$T$$ is greater than the entry of $$d$$.

Warning

Do not mistake this for the inversions of a standard tableau.

EXAMPLES:

sage: t = Tableau([[1,2,3],[2,5]])
sage: t.inversions()
[((1, 1), (0, 0))]
sage: t = Tableau([[1,4,3],[5,2],[2,6],])
sage: t.inversions()
[((0, 1), (0, 2)), ((1, 0), (1, 1)), ((1, 1), (0, 0)), ((2, 1), (1, 0))]

is_column_increasing(weak=False)

Return True if the entries in each column are in increasing order, and False otherwise.

By default, this checks for strictly increasing columns. Set weak to True to test for weakly increasing columns.

EXAMPLES:

sage: T = Tableau([[1, 1, 3], [1, 2]])
sage: T.is_column_increasing(weak=True)
True
sage: T.is_column_increasing()
False
sage: Tableau([, ]).is_column_increasing(weak=True)
False

is_column_strict()

Return True if self is a column strict tableau and False otherwise.

A tableau is column strict if the entries in each column are in (strictly) increasing order.

EXAMPLES:

sage: Tableau([[1, 3], [2, 4]]).is_column_strict()
True
sage: Tableau([[1, 2], [2, 4]]).is_column_strict()
True
sage: Tableau([[2, 3], [2, 4]]).is_column_strict()
False
sage: Tableau([[5, 3], [2, 4]]).is_column_strict()
False
sage: Tableau([]).is_column_strict()
True
sage: Tableau([[1, 4, 2]]).is_column_strict()
True
sage: Tableau([[1, 4, 2], [2, 5]]).is_column_strict()
True
sage: Tableau([[1, 4, 2], [2, 3]]).is_column_strict()
False

is_increasing()

Return True if self is an increasing tableau and False otherwise.

A tableau is increasing if it is both row strict and column strict.

EXAMPLES:

sage: Tableau([[1, 3], [2, 4]]).is_increasing()
True
sage: Tableau([[1, 2], [2, 4]]).is_increasing()
True
sage: Tableau([[2, 3], [2, 4]]).is_increasing()
False
sage: Tableau([[5, 3], [2, 4]]).is_increasing()
False
sage: Tableau([[1, 2, 3], [2, 3], ]).is_increasing()
True

is_k_tableau(k)

Checks whether self is a valid weak $$k$$-tableau.

EXAMPLES:

sage: t = Tableau([[1,2,3],[2,3],])
sage: t.is_k_tableau(3)
True
sage: t = Tableau([[1,1,3],[2,2],])
sage: t.is_k_tableau(3)
False

is_key_tableau()

Return True if self is a key tableau or False otherwise.

A tableau is a key tableau if the set of entries in the $$j$$-th column is a subset of the set of entries in the $$(j-1)$$-st column.

REFERENCES:

EXAMPLES:

sage: t = Tableau([[1,1,1],[2,3],])
sage: t.is_key_tableau()
True

sage: t = Tableau([[1,1,2],[2,3],])
sage: t.is_key_tableau()
False

is_rectangular()

Return True if the tableau self is rectangular and False otherwise.

EXAMPLES:

sage: Tableau([[1,2],[3,4]]).is_rectangular()
True
sage: Tableau([[1,2,3],[4,5],]).is_rectangular()
False
sage: Tableau([]).is_rectangular()
True

is_row_increasing(weak=False)

Return True if the entries in each row are in increasing order, and False otherwise.

By default, this checks for strictly increasing rows. Set weak to True to test for weakly increasing rows.

EXAMPLES:

sage: T = Tableau([[1, 1, 3], [1, 2]])
sage: T.is_row_increasing(weak=True)
True
sage: T.is_row_increasing()
False
sage: Tableau([[2, 1]]).is_row_increasing(weak=True)
False

is_row_strict()

Return True if self is a row strict tableau and False otherwise.

A tableau is row strict if the entries in each row are in (strictly) increasing order.

EXAMPLES:

sage: Tableau([[1, 3], [2, 4]]).is_row_strict()
True
sage: Tableau([[1, 2], [2, 4]]).is_row_strict()
True
sage: Tableau([[2, 3], [2, 4]]).is_row_strict()
True
sage: Tableau([[5, 3], [2, 4]]).is_row_strict()
False

is_semistandard()

Return True if self is a semistandard tableau, and False otherwise.

A tableau is semistandard if its rows weakly increase and its columns strictly increase.

EXAMPLES:

sage: Tableau([[1,1],[1,2]]).is_semistandard()
False
sage: Tableau([[1,2],[1,2]]).is_semistandard()
False
sage: Tableau([[1,1],[2,2]]).is_semistandard()
True
sage: Tableau([[1,2],[2,3]]).is_semistandard()
True
sage: Tableau([[4,1],[3,2]]).is_semistandard()
False

is_standard()

Return True if self is a standard tableau and False otherwise.

EXAMPLES:

sage: Tableau([[1, 3], [2, 4]]).is_standard()
True
sage: Tableau([[1, 2], [2, 4]]).is_standard()
False
sage: Tableau([[2, 3], [2, 4]]).is_standard()
False
sage: Tableau([[5, 3], [2, 4]]).is_standard()
False

k_weight(k)

Return the $$k$$-weight of self.

A tableau has $$k$$-weight $$\alpha = (\alpha_1, ..., \alpha_n)$$ if there are exactly $$\alpha_i$$ distinct residues for the cells occupied by the letter $$i$$ for each $$i$$. The residue of a cell in position $$(a,b)$$ is $$a-b$$ modulo $$k+1$$.

This definition is the one used in [Ive2012] (p. 12).

EXAMPLES:

sage: Tableau([[1,2],[2,3]]).k_weight(1)
[1, 1, 1]
sage: Tableau([[1,2],[2,3]]).k_weight(2)
[1, 2, 1]
sage: t = Tableau([[1,1,1,2,5],[2,3,6],,])
sage: t.k_weight(1)
[2, 1, 1, 1, 1, 1]
sage: t.k_weight(2)
[3, 2, 2, 1, 1, 1]
sage: t.k_weight(3)
[3, 1, 2, 1, 1, 1]
sage: t.k_weight(4)
[3, 2, 2, 1, 1, 1]
sage: t.k_weight(5)
[3, 2, 2, 1, 1, 1]

lambda_catabolism(part)

Return the part-catabolism of self, where part is a partition (which can be just given as an array).

For a partition $$\lambda$$ and a tableau $$T$$, the $$\lambda$$-catabolism of $$T$$ is defined by performing the following steps.

1. Truncate the parts of $$\lambda$$ so that $$\lambda$$ is contained in the shape of $$T$$. Let $$m$$ be the length of this partition.
2. Let $$T_a$$ be the first $$m$$ rows of $$T$$, and $$T_b$$ be the remaining rows.
3. Let $$S_a$$ be the skew tableau $$T_a / \lambda$$.
4. Concatenate the reading words of $$S_a$$ and $$T_b$$, and insert into a tableau.

EXAMPLES:

sage: Tableau([[1,1,3],[2,4,5]]).lambda_catabolism([2,1])
[[3, 5], ]
sage: t = Tableau([[1,1,3,3],[2,3],])
sage: t.lambda_catabolism([])
[[1, 1, 3, 3], [2, 3], ]
sage: t.lambda_catabolism()
[[1, 2, 3, 3, 3], ]
sage: t.lambda_catabolism([1,1])
[[1, 3, 3, 3], ]
sage: t.lambda_catabolism([2,1])
[[3, 3, 3, 3]]
sage: t.lambda_catabolism([4,2,1])
[]
sage: t.lambda_catabolism([5,1])
[[3, 3]]
sage: t.lambda_catabolism([4,1])
[[3, 3]]

last_letter_lequal(tab2)

Return True if self is less than or equal to tab2 in the last letter ordering.

EXAMPLES:

sage: st = StandardTableaux([3,2])
sage: f = lambda b: 1 if b else 0
sage: matrix( [ [ f(t1.last_letter_lequal(t2)) for t2 in st] for t1 in st] )
[1 1 1 1 1]
[0 1 1 1 1]
[0 0 1 1 1]
[0 0 0 1 1]
[0 0 0 0 1]

left_key_tableau()

Return the left key tableau of self.

The left key tableau of a tableau $$T$$ is the key tableau whose entries are weakly lesser than the corresponding entries in $$T$$, and whose column reading word is subject to certain conditions. See [LS1990] for the full definition.

ALGORITHM:

The following algorithm follows [Wil2010]. Note that if $$T$$ is a key tableau then the output of the algorithm is $$T$$.

To compute the left key tableau $$L$$ of a tableau $$T$$ we iterate over the columns of $$T$$. Let $$T_j$$ be the $$j$$-th column of $$T$$ and iterate over the entries in $$T_j$$ from bottom to top. Initialize the corresponding entry $$k$$ in $$L$$ as the largest entry in $$T_j$$. Scan the columns to the left of $$T_j$$ and with each column update $$k$$ to be the lowest entry in that column which is weakly less than $$k$$. Update $$T_j$$ and all columns to the left by removing all scanned entries.

EXAMPLES:

sage: t = Tableau([[1,2],[2,3]])
sage: t.left_key_tableau()
[[1, 1], [2, 2]]
sage: t = Tableau([[1,1,2,4],[2,3,3],,])
sage: t.left_key_tableau()
[[1, 1, 1, 2], [2, 2, 2], , ]

leq(secondtab)

Check whether each entry of self is less-or-equal to the corresponding entry of a further tableau secondtab.

INPUT:

• secondtab – a tableau of the same shape as self

EXAMPLES:

sage: T = Tableau([[1, 2], ])
sage: S = Tableau([[1, 3], ])
sage: G = Tableau([[2, 1], ])
sage: H = Tableau([[1, 2], ])
sage: T.leq(S)
True
sage: T.leq(T)
True
sage: T.leq(G)
False
sage: T.leq(H)
True
sage: S.leq(T)
False
sage: S.leq(G)
False
sage: S.leq(H)
False
sage: G.leq(H)
False
sage: H.leq(G)
False

level()

Returns the level of self, which is always 1.

This function exists mainly for compatibility with TableauTuple.

EXAMPLES:

sage: Tableau([[1,2,3],[4,5]]).level()
1

major_index()

Return the major index of self.

The major index of a tableau $$T$$ is defined to be the sum of the number of descents of T (defined in descents()) with the sum of their legs’ lengths.

Warning

This is not to be confused with the major index of a standard tableau.

EXAMPLES:

sage: Tableau( [[1,4],[2,3]] ).major_index()
1
sage: Tableau( [[1,2],[3,4]] ).major_index()
2


If the major index would be defined in the sense of standard tableaux theory, then the following would give 3 for a result:

sage: Tableau( [[1,2,3],[4,5]] ).major_index()
2

plot(descents=False)

Return a plot self.

INPUT:

• descents – boolean (default: False); if True, then the descents are marked in the tableau; only valid if self is a standard tableau

EXAMPLES:

sage: t = Tableau([[1,2,4],])
sage: t.plot()
Graphics object consisting of 11 graphics primitives
sage: t.plot(descents=True)
Graphics object consisting of 12 graphics primitives

sage: t = Tableau([[2,2,4],])
sage: t.plot()
Graphics object consisting of 11 graphics primitives
sage: t.plot(descents=True)
Traceback (most recent call last):
...
ValueError: the tableau must be standard for 'descents=True'

pp()

Pretty print a string of the tableau.

EXAMPLES:

sage: T = Tableau([[1,2,3],[3,4],])
sage: T.pp()
1  2  3
3  4
5
sage: Tableaux.options.convention="french"
sage: T.pp()
5
3  4
1  2  3
sage: Tableaux.options._reset()

promotion(n)

Return the image of self under the promotion operator.

Warning

You might know this operator as the inverse promotion operator – literature does not agree on the name. You might also be looking for the Lapointe-Lascoux-Morse promotion operator (promotion_operator()).

The promotion operator, applied to a tableau $$t$$, does the following:

Iterate over all letters $$n+1$$ in the tableau $$t$$, from left to right. For each of these letters, do the following:

• Remove the letter from $$t$$, thus leaving a hole where it used to be.
• Apply jeu de taquin to move this hole southwest (in French notation) until it reaches the inner boundary of $$t$$.
• Fill $$0$$ into the hole once jeu de taquin has completed.

Once this all is done, add $$1$$ to each letter in the tableau. This is not always well-defined. Restricted to the class of semistandard tableaux whose entries are all $$\leq n + 1$$, this is the usual promotion operator defined on this class.

When self is a standard tableau of size n + 1, this definition of promotion is precisely the one given in [Hai1992] (p. 90). It is the inverse of the maps called “promotion” in [Sag2011] (p. 23) and in [Stan2009].

Warning

To my (Darij’s) knowledge, the fact that the above promotion operator really is the inverse of the “inverse promotion operator” promotion_inverse() for semistandard tableaux has never been proven in literature. Corrections are welcome.

REFERENCES:

EXAMPLES:

sage: t = Tableau([[1,2],[3,3]])
sage: t.promotion(2)
[[1, 1], [2, 3]]

sage: t = Tableau([[1,1,1],[2,2,3],[3,4,4]])
sage: t.promotion(3)
[[1, 1, 2], [2, 2, 3], [3, 4, 4]]

sage: t = Tableau([[1,2],])
sage: t.promotion(3)
[[2, 3], ]

sage: t = Tableau([[1,1,3],[2,2]])
sage: t.promotion(2)
[[1, 2, 2], [3, 3]]

sage: t = Tableau([[1,1,3],[2,3]])
sage: t.promotion(2)
[[1, 1, 2], [2, 3]]

sage: t = Tableau([])
sage: t.promotion(2)
[]

promotion_inverse(n)

Return the image of self under the inverse promotion operator.

Warning

You might know this operator as the promotion operator (without “inverse”) – literature does not agree on the name.

The inverse promotion operator, applied to a tableau $$t$$, does the following:

Iterate over all letters $$1$$ in the tableau $$t$$, from right to left. For each of these letters, do the following:

• Remove the letter from $$t$$, thus leaving a hole where it used to be.
• Apply jeu de taquin to move this hole northeast (in French notation) until it reaches the outer boundary of $$t$$.
• Fill $$n+2$$ into the hole once jeu de taquin has completed.

Once this all is done, subtract $$1$$ from each letter in the tableau. This is not always well-defined. Restricted to the class of semistandard tableaux whose entries are all $$\leq n + 1$$, this is the usual inverse promotion operator defined on this class.

When self is a standard tableau of size n + 1, this definition of inverse promotion is the map called “promotion” in [Sag2011] (p. 23) and in [Stan2009], and is the inverse of the map called “promotion” in [Hai1992] (p. 90).

Warning

To my (Darij’s) knowledge, the fact that the above “inverse promotion operator” really is the inverse of the promotion operator promotion() for semistandard tableaux has never been proven in literature. Corrections are welcome.

EXAMPLES:

sage: t = Tableau([[1,2],[3,3]])
sage: t.promotion_inverse(2)
[[1, 2], [2, 3]]

sage: t = Tableau([[1,2],[2,3]])
sage: t.promotion_inverse(2)
[[1, 1], [2, 3]]

sage: t = Tableau([[1,2,5],[3,3,6],[4,7]])
sage: t.promotion_inverse(8)
[[1, 2, 4], [2, 5, 9], [3, 6]]

sage: t = Tableau([])
sage: t.promotion_inverse(2)
[]

promotion_operator(i)

Return a list of semistandard tableaux obtained by the $$i$$-th Lapointe-Lascoux-Morse promotion operator from the semistandard tableau self.

Warning

This is not Schuetzenberger’s jeu-de-taquin promotion! For the latter, see promotion() and promotion_inverse().

This operator is defined by taking the maximum entry $$m$$ of $$T$$, then adding a horizontal $$i$$-strip to $$T$$ in all possible ways, each time filling this strip with $$m+1$$’s, and finally letting the permutation $$\sigma_1 \sigma_2 \cdots \sigma_m = (2, 3, \ldots, m+1, 1)$$ act on each of the resulting tableaux via the Lascoux-Schuetzenberger action (symmetric_group_action_on_values()). This method returns the list of all resulting tableaux. See [LLM2003] for the purpose of this operator.

EXAMPLES:

sage: t = Tableau([[1,2],])
sage: t.promotion_operator(1)
[[[1, 2], , ], [[1, 2], [3, 4]], [[1, 2, 4], ]]
sage: t.promotion_operator(2)
[[[1, 1], [2, 3], ],
[[1, 1, 2], , ],
[[1, 1, 4], [2, 3]],
[[1, 1, 2, 4], ]]
sage: Tableau([]).promotion_operator(2)
[[[1, 1], ], [[1, 1, 2]]]
sage: Tableau([[1,1],]).promotion_operator(3)
[[[1, 1, 1], [2, 2], ],
[[1, 1, 1, 2], , ],
[[1, 1, 1, 3], [2, 2]],
[[1, 1, 1, 2, 3], ]]


The example from [LLM2003] p. 12:

sage: Tableau([[1,1],[2,2]]).promotion_operator(3)
[[[1, 1, 1], [2, 2], [3, 3]],
[[1, 1, 1, 3], [2, 2], ],
[[1, 1, 1, 3, 3], [2, 2]]]

raise_action_from_words(f, *args)

EXAMPLES:

sage: from sage.combinat.tableau import symmetric_group_action_on_values
sage: import functools
sage: t = Tableau([[1,1,3,3],[2,3],])
sage: f = functools.partial(t.raise_action_from_words, symmetric_group_action_on_values)
sage: f([1,2,3])
[[1, 1, 3, 3], [2, 3], ]
sage: f([3,2,1])
[[1, 1, 1, 1], [2, 3], ]
sage: f([1,3,2])
[[1, 1, 2, 2], [2, 2], ]

reading_word_permutation()

Return the permutation obtained by reading the entries of the standardization of self row by row, starting with the bottommost row (in English notation).

EXAMPLES:

sage: StandardTableau([[1,2],[3,4]]).reading_word_permutation()
[3, 4, 1, 2]


Check that trac ticket #14724 is fixed:

sage: SemistandardTableau([[1,1]]).reading_word_permutation()
[1, 2]

reduced_column_word()

Return the lexicographically minimal reduced expression for the permutation that maps the conjugate of the initial_tableau() to self.

Ths reduced expression is a minimal length coset representative for the corresponding Young subgroup. In one line notation, the permutation is obtained by concatenating the columns of the tableau in order from top to bottom.

EXAMPLES:

sage: StandardTableau([[1,4,6],[2,5],]).reduced_column_word()
[]
sage: StandardTableau([[1,4,5],[2,6],]).reduced_column_word()

sage: StandardTableau([[1,3,6],[2,5],]).reduced_column_word()

sage: StandardTableau([[1,3,5],[2,6],]).reduced_column_word()
[3, 5]
sage: StandardTableau([[1,2,5],[3,6],]).reduced_column_word()
[3, 2, 5]

reduced_lambda_catabolism(part)

EXAMPLES:

sage: t = Tableau([[1,1,3,3],[2,3],])
sage: t.reduced_lambda_catabolism([])
[[1, 1, 3, 3], [2, 3], ]
sage: t.reduced_lambda_catabolism()
[[1, 2, 3, 3, 3], ]
sage: t.reduced_lambda_catabolism([1,1])
[[1, 3, 3, 3], ]
sage: t.reduced_lambda_catabolism([2,1])
[[3, 3, 3, 3]]
sage: t.reduced_lambda_catabolism([4,2,1])
[]
sage: t.reduced_lambda_catabolism([5,1])
0
sage: t.reduced_lambda_catabolism([4,1])
0

reduced_row_word()

Return the lexicographically minimal reduced expression for the permutation that maps the initial_tableau() to self.

Ths reduced expression is a minimal length coset representative for the corresponding Young subgroup. In one line notation, the permutation is obtained by concatenating the rows of the tableau in order from top to bottom.

EXAMPLES:

sage: StandardTableau([[1,2,3],[4,5],]).reduced_row_word()
[]
sage: StandardTableau([[1,2,3],[4,6],]).reduced_row_word()

sage: StandardTableau([[1,2,4],[3,6],]).reduced_row_word()
[3, 5]
sage: StandardTableau([[1,2,5],[3,6],]).reduced_row_word()
[3, 5, 4]
sage: StandardTableau([[1,2,6],[3,5],]).reduced_row_word()
[3, 4, 5, 4]

residue(k, e, multicharge=(0, ))

Return the residue of the integer k in the tableau self.

The residue of $$k$$ in a standard tableau is $$c - r + m$$ in $$\ZZ / e\ZZ$$, where $$k$$ appears in row $$r$$ and column $$c$$ of the tableau with multicharge $$m$$.

INPUT:

• k – an integer in $$\{1, 2, \ldots, n\}$$
• e – an integer in $$\{0, 2, 3, 4, 5, \ldots\}$$
• multicharge – (default: ) a list of length 1

Here $$n$$ is its size of self.

The multicharge is a list of length 1 which gives an offset for all of the contents. It is included mainly for compatibility with residue().

OUTPUT:

The residue in $$\ZZ / e\ZZ$$.

EXAMPLES:

sage: StandardTableau([[1,2,5],[3,4]]).residue(1,3)
0
sage: StandardTableau([[1,2,5],[3,4]]).residue(2,3)
1
sage: StandardTableau([[1,2,5],[3,4]]).residue(3,3)
2
sage: StandardTableau([[1,2,5],[3,4]]).residue(4,3)
0
sage: StandardTableau([[1,2,5],[3,4]]).residue(5,3)
2
sage: StandardTableau([[1,2,5],[3,4]]).residue(6,3)
Traceback (most recent call last):
...
ValueError: 6 does not appear in the tableau

residue_sequence(e, multicharge=(0, ))

Return the sage.combinat.tableau_residues.ResidueSequence of the tableau self.

INPUT:

• e – an integer in $$\{0, 2, 3, 4, 5, \ldots\}$$
• multicharge – (default: ) a sequence of integers of length 1

The $$multicharge$$ is a list of length 1 which gives an offset for all of the contents. It is included mainly for compatibility with residue().

OUTPUT:

The corresponding residue sequence of the tableau; see ResidueSequence.

EXAMPLES:

sage: StandardTableauTuple([[1,2],[3,4]]).residue_sequence(2)
2-residue sequence (0,1,1,0) with multicharge (0)
sage: StandardTableauTuple([[1,2],[3,4]]).residue_sequence(3)
3-residue sequence (0,1,2,0) with multicharge (0)
sage: StandardTableauTuple([[1,2],[3,4]]).residue_sequence(4)
4-residue sequence (0,1,3,0) with multicharge (0)

restrict(n)

Return the restriction of the semistandard tableau self to n. If possible, the restricted tableau will have the same parent as this tableau.

If $$T$$ is a semistandard tableau and $$n$$ is a nonnegative integer, then the restriction of $$T$$ to $$n$$ is defined as the (semistandard) tableau obtained by removing all cells filled with entries greater than $$n$$ from $$T$$.

Note

If only the shape of the restriction, rather than the whole restriction, is needed, then the faster method restriction_shape() is preferred.

EXAMPLES:

sage: Tableau([[1,2],,]).restrict(3)
[[1, 2], ]
sage: StandardTableau([[1,2],,]).restrict(2)
[[1, 2]]
sage: Tableau([[1,2,3],[2,4,4],]).restrict(0)
[]
sage: Tableau([[1,2,3],[2,4,4],]).restrict(2)
[[1, 2], ]
sage: Tableau([[1,2,3],[2,4,4],]).restrict(3)
[[1, 2, 3], , ]
sage: Tableau([[1,2,3],[2,4,4],]).restrict(5)
[[1, 2, 3], [2, 4, 4], ]


If possible the restricted tableau will belong to the same category as the original tableau:

sage: S=StandardTableau([[1,2,4,7],[3,5],]); S.category()
Category of elements of Standard tableaux
sage: S.restrict(4).category()
Category of elements of Standard tableaux
sage: SS=StandardTableaux([4,2,1])([[1,2,4,7],[3,5],]); SS.category()
Category of elements of Standard tableaux of shape [4, 2, 1]
sage: SS.restrict(4).category()
Category of elements of Standard tableaux

sage: Tableau([[1,2],,]).restrict(3)
[[1, 2], ]
sage: Tableau([[1,2],,]).restrict(2)
[[1, 2]]
sage: SemistandardTableau([[1,1],]).restrict(1)
[[1, 1]]
sage: _.category()
Category of elements of Semistandard tableaux

restriction_shape(n)

Return the shape of the restriction of the semistandard tableau self to n.

If $$T$$ is a semistandard tableau and $$n$$ is a nonnegative integer, then the restriction of $$T$$ to $$n$$ is defined as the (semistandard) tableau obtained by removing all cells filled with entries greater than $$n$$ from $$T$$.

This method computes merely the shape of the restriction. For the restriction itself, use restrict().

EXAMPLES:

sage: Tableau([[1,2],[2,3],[3,4]]).restriction_shape(3)
[2, 2, 1]
sage: StandardTableau([[1,2],,,]).restriction_shape(2)

sage: Tableau([[1,3,3,5],[2,4,4],]).restriction_shape(0)
[]
sage: Tableau([[1,3,3,5],[2,4,4],]).restriction_shape(2)
[1, 1]
sage: Tableau([[1,3,3,5],[2,4,4],]).restriction_shape(3)
[3, 1]
sage: Tableau([[1,3,3,5],[2,4,4],]).restriction_shape(5)
[4, 3]

sage: all( T.restriction_shape(i) == T.restrict(i).shape()
....:      for T in StandardTableaux(5) for i in range(1, 5) )
True

reverse_bump(loc)

Reverse row bump the entry of self at the specified location loc (given as a row index or a corner (r, c) of the tableau).

This is the reverse of Schensted’s row-insertion algorithm. See Section 1.1, page 8, of Fulton’s [Ful1997].

INPUT:

• loc – Can be either of the following:

• The coordinates (r, c) of the square to reverse-bump (which must be a corner of the tableau);
• The row index r of this square.

Note that both r and c are $$0$$-based, i.e., the topmost row and the leftmost column are the $$0$$-th row and the $$0$$-th column.

OUTPUT:

An ordered pair consisting of:

1. The resulting (smaller) tableau;
2. The entry bumped out at the end of the process.

EXAMPLES:

This is the reverse of Schensted’s bump:

sage: T = Tableau([[1, 1, 2, 2, 4], [2, 3, 3], [3, 4], ])
sage: T.reverse_bump(2)
([[1, 1, 2, 3, 4], [2, 3, 4], , ], 2)
sage: T == T.reverse_bump(2).bump(2)
True
sage: T.reverse_bump((3, 0))
([[1, 2, 2, 2, 4], [3, 3, 3], [4, 4]], 1)


Some errors caused by wrong input:

sage: T.reverse_bump((3, 1))
Traceback (most recent call last):
...
ValueError: invalid corner
sage: T.reverse_bump(4)
Traceback (most recent call last):
...
IndexError: list index out of range
sage: Tableau([[2, 2, 1], [3, 3]]).reverse_bump(0)
Traceback (most recent call last):
...
ValueError: Reverse bumping is only defined for semistandard tableaux


Some edge cases:

sage: Tableau([]).reverse_bump(0)
([], 1)
sage: Tableau([[1,1]]).reverse_bump(0)
([], 1)
sage: Tableau([]).reverse_bump(0)
Traceback (most recent call last):
...
IndexError: list index out of range


Note

Reverse row bumping is only implemented for tableaux with weakly increasing and strictly increasing columns (though the tableau does not need to be an instance of class SemistandardTableau).

right_key_tableau()

Return the right key tableau of self.

The right key tableau of a tableau $$T$$ is a key tableau whose entries are weakly greater than the corresponding entries in $$T$$, and whose column reading word is subject to certain conditions. See [LS1990] for the full definition.

ALGORITHM:

The following algorithm follows [Wil2010]. Note that if $$T$$ is a key tableau then the output of the algorithm is $$T$$.

To compute the right key tableau $$R$$ of a tableau $$T$$ we iterate over the columns of $$T$$. Let $$T_j$$ be the $$j$$-th column of $$T$$ and iterate over the entries in $$T_j$$ from bottom to top. Initialize the corresponding entry $$k$$ in $$R$$ to be the largest entry in $$T_j$$. Scan the bottom of each column of $$T$$ to the right of $$T_j$$, updating $$k$$ to be the scanned entry whenever the scanned entry is weakly greater than $$k$$. Update $$T_j$$ and all columns to the right by removing all scanned entries.

EXAMPLES:

sage: t = Tableau([[1,2],[2,3]])
sage: t.right_key_tableau()
[[2, 2], [3, 3]]
sage: t = Tableau([[1,1,2,4],[2,3,3],,])
sage: t.right_key_tableau()
[[2, 2, 2, 4], [3, 4, 4], , ]

rotate_180()

Return the tableau obtained by rotating self by $$180$$ degrees.

This only works for rectangular tableaux.

EXAMPLES:

sage: Tableau([[1,2],[3,4]]).rotate_180()
[[4, 3], [2, 1]]

row_stabilizer()

Return the PermutationGroup corresponding to the row stabilizer of self.

This assumes that every integer from $$1$$ to the size of self appears exactly once in self.

EXAMPLES:

sage: rs = Tableau([[1,2,3],[4,5]]).row_stabilizer()
sage: rs.order() == factorial(3)*factorial(2)
True
sage: PermutationGroupElement([(1,3,2),(4,5)]) in rs
True
sage: PermutationGroupElement([(1,4)]) in rs
False
sage: rs = Tableau([[1, 2],]).row_stabilizer()
sage: PermutationGroupElement([(1,2),(3,)]) in rs
True
sage: rs.one().domain()
[1, 2, 3]
sage: rs = Tableau([,,]).row_stabilizer()
sage: rs.order()
1
sage: rs = Tableau([[2,4,5],[1,3]]).row_stabilizer()
sage: rs.order()
12
sage: rs = Tableau([]).row_stabilizer()
sage: rs.order()
1

schensted_insert(i, left=False)

Insert i into self using Schensted’s row-bumping (or row-insertion) algorithm.

INPUT:

• i – a number to insert
• left – (default: False) boolean; if set to True, the insertion will be done from the left. That is, if one thinks of the algorithm as appending a letter to the reading word of self, we append the letter to the left instead of the right

EXAMPLES:

sage: t = Tableau([[3,5],])
sage: t.schensted_insert(8)
[[3, 5, 8], ]
sage: t.schensted_insert(8, left=True)
[[3, 5], , ]

schuetzenberger_involution(n=None, check=True)

Return the Schuetzenberger involution of the tableau self.

This method relies on the analogous method on words, which reverts the word and then complements all letters within the underlying ordered alphabet. If $$n$$ is specified, the underlying alphabet is assumed to be $$[1, 2, \ldots, n]$$. If no alphabet is specified, $$n$$ is the maximal letter appearing in self.

INPUT:

• n – an integer specifying the maximal letter in the alphabet (optional)
• check – (Default: True) Check to make sure self is semistandard. Set to False to avoid this check. (optional)

OUTPUT:

• a tableau, the Schuetzenberger involution of self

EXAMPLES:

sage: t = Tableau([[1,1,1],[2,2]])
sage: t.schuetzenberger_involution(3)
[[2, 2, 3], [3, 3]]

sage: t = Tableau([[1,2,3],[4,5]])
sage: t.schuetzenberger_involution()
[[1, 2, 5], [3, 4]]

sage: t = Tableau([[1,3,5,7],[2,4,6],[8,9]])
sage: t.schuetzenberger_involution()
[[1, 2, 6, 8], [3, 4, 9], [5, 7]]

sage: t = Tableau([])
sage: t.schuetzenberger_involution()
[]

sage: t = StandardTableau([[1,2,3],[4,5]])
sage: s = t.schuetzenberger_involution()
sage: s.parent()
Standard tableaux

seg()

Return the total number of segments in self, as in [Sal2014].

Let $$T$$ be a tableaux. We define a $$k$$-segment of $$T$$ (in the $$i$$-th row) to be a maximal consecutive sequence of $$k$$-boxes in the $$i$$-th row for any $$i+1 \le k \le r+1$$. Denote the total number of $$k$$-segments in $$T$$ by $$\mathrm{seg}(T)$$.

REFERENCES:

EXAMPLES:

sage: t = Tableau([[1,1,2,3,5],[2,3,5,5],[3,4]])
sage: t.seg()
6

sage: B = crystals.Tableaux("A4",shape=[4,3,2,1])
sage: t = B.to_tableau()
sage: t.seg()
3

shape()

Return the shape of a tableau self.

EXAMPLES:

sage: Tableau([[1,2,3],[4,5],]).shape()
[3, 2, 1]

size()

Return the size of the shape of the tableau self.

EXAMPLES:

sage: Tableau([[1, 4, 6], [2, 5], ]).size()
6
sage: Tableau([[1, 3], [2, 4]]).size()
4

slide_multiply(left, right)

Multiply two tableaux using jeu de taquin.

This product makes the set of semistandard tableaux into an associative monoid. The empty tableau is the unit in this monoid.

See pp. 15 of [Ful1997].

The same product operation is implemented in a different way in bump_multiply().

EXAMPLES:

sage: t = Tableau([[1,2,2,3],[2,3,5,5],[4,4,6],[5,6]])
sage: t2 = Tableau([[1,2],])
sage: t.slide_multiply(t2)
[[1, 1, 2, 2, 3], [2, 2, 3, 5], [3, 4, 5], [4, 6, 6], ]

socle()

EXAMPLES:

sage: Tableau([[1,2],[3,4]]).socle()
2
sage: Tableau([[1,2,3,4]]).socle()
4

standardization(check=True)

Return the standardization of self, assuming self is a semistandard tableau.

The standardization of a semistandard tableau $$T$$ is the standard tableau $$\mathrm{st}(T)$$ of the same shape as $$T$$ whose reversed reading word is the standardization of the reversed reading word of $$T$$.

The standardization of a word $$w$$ can be formed by replacing all $$1$$’s in $$w$$ by $$1, 2, \ldots, k_1$$ from left to right, all $$2$$’s in $$w$$ by $$k_1 + 1, k_1 + 2, \ldots, k_2$$, and repeating for all letters which appear in $$w$$. See also Word.standard_permutation().

INPUT:

• check – (Default: True) Check to make sure self is semistandard. Set to False to avoid this check.

EXAMPLES:

sage: t = Tableau([[1,3,3,4],[2,4,4],[5,16]])
sage: t.standardization()
[[1, 3, 4, 7], [2, 5, 6], [8, 9]]


Standard tableaux are fixed under standardization:

sage: all((t == t.standardization() for t in StandardTableaux(6)))
True
sage: t = Tableau([])
sage: t.standardization()
[]


The reading word of the standardization is the standardization of the reading word:

sage: T = SemistandardTableaux(shape=[6,3,3,1], max_entry=5)
sage: all(t.to_word().standard_permutation() == t.standardization().reading_word_permutation() for t in T) # long time
True

sulzgruber_correspondence()

Return the image of the $$\lambda$$-array self under the Sulzgruber correspondence (as a WeakReversePlanePartition).

This relies on interpreting self as a $$\lambda$$-array in the sense of hillman_grassl. See hillman_grassl for definitions of the objects involved.

The Sulzgruber correspondence is the map $$\Phi_\lambda$$ from [Sulzgr2017] Section 7, and is the map $$\xi_\lambda^{-1}$$ from [Pak2002] Section 5. It is denoted by $$\mathcal{RSK}$$ in [Hopkins2017]. It is the inverse of the Pak correspondence (pak_correspondence()). The following description of the Sulzgruber correspondence follows [Hopkins2017] (which denotes it by $$\mathcal{RSK}$$):

Fix a partition $$\lambda$$ (see Partition()). We draw all partitions and tableaux in English notation.

A $$\lambda$$-array will mean a tableau of shape $$\lambda$$ whose entries are nonnegative integers. (No conditions on the order of these entries are made. Note that $$0$$ is allowed.)

A weak reverse plane partition of shape $$\lambda$$ (short: $$\lambda$$-rpp) will mean a $$\lambda$$-array whose entries weakly increase along each row and weakly increase along each column.

We shall also use the following notation: If $$(u, v)$$ is a cell of $$\lambda$$, and if $$\pi$$ is a $$\lambda$$-rpp, then:

• the lower bound of $$\pi$$ at $$(u, v)$$ (denoted by $$\pi_{<(u, v)}$$) is defined to be $$\max \{ \pi_{u-1, v} , \pi_{u, v-1} \}$$ (where $$\pi_{0, v}$$ and $$\pi_{u, 0}$$ are understood to mean $$0$$).
• the upper bound of $$\pi$$ at $$(u, v)$$ (denoted by $$\pi_{>(u, v)}$$) is defined to be $$\min \{ \pi_{u+1, v} , \pi_{u, v+1} \}$$ (where $$\pi_{i, j}$$ is understood to mean $$+ \infty$$ if $$(i, j)$$ is not in $$\lambda$$; thus, the upper bound at a corner cell is $$+ \infty$$).
• toggling $$\pi$$ at $$(u, v)$$ means replacing the entry $$\pi_{u, v}$$ of $$\pi$$ at $$(u, v)$$ by $$\pi_{<(u, v)} + \pi_{>(u, v)} - \pi_{u, v}$$ (this is well-defined as long as $$(u, v)$$ is not a corner of $$\lambda$$).

Note that every $$\lambda$$-rpp $$\pi$$ and every cell $$(u, v)$$ of $$\lambda$$ satisfy $$\pi_{<(u, v)} \leq \pi_{u, v} \leq \pi_{>(u, v)}$$. Note that toggling a $$\lambda$$-rpp (at a cell that is not a corner) always results in a $$\lambda$$-rpp. Also, toggling is an involution).

The Pak correspondence $$\xi_\lambda$$ sends a $$\lambda$$-rpp $$\pi$$ to a $$\lambda$$-array $$\xi_\lambda(\pi)$$. It is defined by recursion on $$\lambda$$ (that is, we assume that $$\xi_\mu$$ is already defined for every partition $$\mu$$ smaller than $$\lambda$$), and its definition proceeds as follows:

• If $$\lambda = \varnothing$$, then $$\xi_\lambda$$ is the obvious bijection sending the only $$\varnothing$$-rpp to the only $$\varnothing$$-array.
• Pick any corner $$c = (i, j)$$ of $$\lambda$$, and let $$\mu$$ be the result of removing this corner $$c$$ from the partition $$\lambda$$. (The exact choice of $$c$$ is immaterial.)
• Let $$\pi'$$ be what remains of $$\pi$$ when the corner cell $$c$$ is removed.
• For each positive integer $$k$$ such that $$(i-k, j-k)$$ is a cell of $$\lambda$$, toggle $$\pi'$$ at $$(i-k, j-k)$$. (All these togglings commute, so the order in which they are made is immaterial.)
• Let $$M = \xi_\mu(\pi')$$.
• Extend the $$\mu$$-array $$M$$ to a $$\lambda$$-array $$M'$$ by adding the cell $$c$$ and writing the number $$\pi_{i, j} - \pi_{<(i, j)}$$ into this cell.
• Set $$\xi_\lambda(\pi) = M'$$.

sulzgruber_correspondence() for the Sulzgruber correspondence as a standalone function.

pak_correspondence() for the inverse map.

EXAMPLES:

sage: a = Tableau([[2, 1, 1], [0, 2, 0], [1, 1]])
sage: A = a.sulzgruber_correspondence(); A
[[0, 1, 4], [1, 5, 5], [3, 6]]
sage: A.parent(), a.parent()
(Weak Reverse Plane Partitions, Tableaux)

sage: a = Tableau([[1, 3], [0, 1]])
sage: a.sulzgruber_correspondence()
[[0, 4], [1, 5]]

symmetric_group_action_on_entries(w)

Return the tableau obtained form this tableau by acting by the permutation w.

Let $$T$$ be a standard tableau of size $$n$$, then the action of $$w \in S_n$$ is defined by permuting the entries of $$T$$ (recall they are $$1, 2, \ldots, n$$). In particular, suppose the entry at cell $$(i, j)$$ is $$a$$, then the entry becomes $$w(a)$$. In general, the resulting tableau $$wT$$ may not be standard.

Note

This is different than symmetric_group_action_on_values() which is defined on semistandard tableaux and is guaranteed to return a semistandard tableau.

INPUT:

• w – a permutation

EXAMPLES:

sage: StandardTableau([[1,2,4],[3,5]]).symmetric_group_action_on_entries( Permutation(((4,5))) )
[[1, 2, 5], [3, 4]]
sage: _.category()
Category of elements of Standard tableaux
sage: StandardTableau([[1,2,4],[3,5]]).symmetric_group_action_on_entries( Permutation(((1,2))) )
[[2, 1, 4], [3, 5]]
sage: _.category()
Category of elements of Tableaux

symmetric_group_action_on_values(perm)

Return the image of the semistandard tableau self under the action of the permutation perm using the Lascoux-Schuetzenberger action of the symmetric group $$S_n$$ on the semistandard tableaux with ceiling $$n$$.

If $$n$$ is a nonnegative integer, then the Lascoux-Schuetzenberger action is a group action of the symmetric group $$S_n$$ on the set of semistandard Young tableaux with ceiling $$n$$ (that is, with entries taken from the set $$\{1, 2, \ldots, n\}$$). It is defined as follows:

Let $$i \in \{1, 2, \ldots, n-1\}$$, and let $$T$$ be a semistandard tableau with ceiling $$n$$. Let $$w$$ be the reading word (to_word()) of $$T$$. Replace all letters $$i$$ in $$w$$ by closing parentheses, and all letters $$i+1$$ in $$w$$ by opening parentheses. Whenever an opening parenthesis stands left of a closing parenthesis without there being any parentheses in between (it is allowed to have letters in-between as long as they are not parentheses), consider these two parentheses as matched with each other, and replace them back by the letters $$i+1$$ and $$i$$. Repeat this procedure until there are no more opening parentheses standing left of closing parentheses. Then, let $$a$$ be the number of opening parentheses in the word, and $$b$$ the number of closing parentheses (notice that all opening parentheses are right of all closing parentheses). Replace the first $$a$$ parentheses by the letters $$i$$, and replace the remaining $$b$$ parentheses by the letters $$i+1$$. Let $$w'$$ be the resulting word. Let $$T'$$ be the tableau with the same shape as $$T$$ but with reading word $$w'$$. This tableau $$T'$$ can be shown to be semistandard. We define the image of $$T$$ under the action of the simple transposition $$s_i = (i, i+1) \in S_n$$ to be this tableau $$T'$$. It can be shown that these actions of the transpositions $$s_1, s_2, \ldots, s_{n-1}$$ satisfy the Moore-Coxeter relations of $$S_n$$, and thus this extends to a unique action of the symmetric group $$S_n$$ on the set of semistandard tableaux with ceiling $$n$$. This is the Lascoux-Schuetzenberger action.

This action of the symmetric group $$S_n$$ on the set of all semistandard tableaux of given shape $$\lambda$$ with entries in $$\{ 1, 2, \ldots, n \}$$ is the one defined in [Loth02] Theorem 5.6.3. In particular, the action of $$s_i$$ is denoted by $$\sigma_i$$ in said source. (Beware of the typo in the definition of $$\sigma_i$$: it should say $$\sigma_i ( a_i^r a_{i+1}^s ) = a_i^s a_{i+1}^r$$, not $$\sigma_i ( a_i^r a_{i+1}^s ) = a_i^s a_{i+1}^s$$.)

EXAMPLES:

sage: t = Tableau([[1,1,3,3],[2,3],])
sage: t.symmetric_group_action_on_values([1,2,3])
[[1, 1, 3, 3], [2, 3], ]
sage: t.symmetric_group_action_on_values([2,1,3])
[[1, 2, 3, 3], [2, 3], ]
sage: t.symmetric_group_action_on_values([3,1,2])
[[1, 2, 2, 2], [2, 3], ]
sage: t.symmetric_group_action_on_values([2,3,1])
[[1, 1, 1, 1], [2, 2], ]
sage: t.symmetric_group_action_on_values([3,2,1])
[[1, 1, 1, 1], [2, 3], ]
sage: t.symmetric_group_action_on_values([1,3,2])
[[1, 1, 2, 2], [2, 2], ]

to_Gelfand_Tsetlin_pattern()

Return the Gelfand-Tsetlin pattern corresponding to self when semistandard.

EXAMPLES:

sage: T = Tableau([[1,2,3],[2,3],])
sage: G = T.to_Gelfand_Tsetlin_pattern(); G
[[3, 2, 1], [2, 1], ]
sage: G.to_tableau() == T
True
sage: T = Tableau([[1,3],])
sage: T.to_Gelfand_Tsetlin_pattern()
[[2, 1, 0], [1, 1], ]

to_chain(max_entry=None)

Return the chain of partitions corresponding to the (semi)standard tableau self.

The optional keyword parameter max_entry can be used to customize the length of the chain. Specifically, if this parameter is set to a nonnegative integer n, then the chain is constructed from the positions of the letters $$1, 2, \ldots, n$$ in the tableau.

EXAMPLES:

sage: Tableau([[1,2],,]).to_chain()
[[], , , [2, 1], [2, 1, 1]]
sage: Tableau([[1,1],]).to_chain()
[[], , [2, 1]]
sage: Tableau([[1,1],]).to_chain()
[[], , , [2, 1]]
sage: Tableau([]).to_chain()
[[]]
sage: Tableau([[1,1],,]).to_chain(max_entry=2)
[[], , [2, 1]]
sage: Tableau([[1,1],,]).to_chain(max_entry=3)
[[], , [2, 1], [2, 1, 1]]
sage: Tableau([[1,1],,]).to_chain(max_entry=4)
[[], , [2, 1], [2, 1, 1], [2, 1, 1]]
sage: Tableau([[1,1,2],[2,3],[4,5]]).to_chain(max_entry=6)
[[], , [3, 1], [3, 2], [3, 2, 1], [3, 2, 2], [3, 2, 2]]

to_list()

Return self as a list of lists (not tuples!).

EXAMPLES:

sage: t = Tableau([[1,2],[3,4]])
sage: l = t.to_list(); l
[[1, 2], [3, 4]]
sage: l = 2
sage: t
[[1, 2], [3, 4]]

to_sign_matrix(max_entry=None)

Return the sign matrix of self.

A sign matrix is an $$m \times n$$ matrix of 0’s, 1’s and -1’s such that the partial sums of each column is either 0 or 1 and the partial sums of each row is non-negative. [Ava2007]

INPUT:

• max_entry – A non-negative integer, the maximum allowable number in the tableau. Defaults to the largest entry in the tableau if not specified.

EXAMPLES:

sage: t = SemistandardTableau([[1,1,1,2,4],[3,3,4],[4,5],[6,6]])
sage: t.to_sign_matrix(6)
[ 0  0  0  1  0  0]
[ 0  1  0 -1  0  0]
[ 1 -1  0  1  0  0]
[ 0  0  1 -1  1  1]
[ 0  0  0  1 -1  0]
sage: t = Tableau([[1,2,4],[3,5]])
sage: t.to_sign_matrix(7)
[ 0  0  0  1  0  0  0]
[ 0  1  0 -1  1  0  0]
[ 1 -1  1  0 -1  0  0]
sage: t=Tableau([(4,5,4,3),(2,1,3)])
sage: t.to_sign_matrix(5)
[ 0  0  1  0  0]
[ 0  0  0  1  0]
[ 1  0 -1 -1  1]
[-1  1  0  1 -1]
sage: s=Tableau([(1,0,-2,4),(3,4,5)])
sage: s.to_sign_matrix(6)
Traceback (most recent call last):
...
ValueError: the entries must be non-negative integers

to_word()

An alias for to_word_by_row().

EXAMPLES:

sage: Tableau([[1,2],[3,4]]).to_word()
word: 3412
sage: Tableau([[1, 4, 6], [2, 5], ]).to_word()
word: 325146

to_word_by_column()

Return the word obtained from a column reading of the tableau self (starting with the leftmost column, reading every column from bottom to top).

EXAMPLES:

sage: Tableau([[1,2],[3,4]]).to_word_by_column()
word: 3142
sage: Tableau([[1, 4, 6], [2, 5], ]).to_word_by_column()
word: 321546

to_word_by_row()

Return the word obtained from a row reading of the tableau self (starting with the lowermost row, reading every row from left to right).

EXAMPLES:

sage: Tableau([[1,2],[3,4]]).to_word_by_row()
word: 3412
sage: Tableau([[1, 4, 6], [2, 5], ]).to_word_by_row()
word: 325146

vertical_flip()

Return the tableau obtained by vertically flipping the tableau self.

This only works for rectangular tableaux.

EXAMPLES:

sage: Tableau([[1,2],[3,4]]).vertical_flip()
[[3, 4], [1, 2]]

weight()

Return the weight of the tableau self. Trailing zeroes are omitted when returning the weight.

The weight of a tableau $$T$$ is the sequence $$(a_1, a_2, a_3, \ldots )$$, where $$a_k$$ is the number of entries of $$T$$ equal to $$k$$. This sequence contains only finitely many nonzero entries.

The weight of a tableau $$T$$ is the same as the weight of the reading word of $$T$$, for any reading order.

EXAMPLES:

sage: Tableau([[1,2],[3,4]]).weight()
[1, 1, 1, 1]

sage: Tableau([]).weight()
[]

sage: Tableau([[1,3,3,7],[4,2],[2,3]]).weight()
[1, 2, 3, 1, 0, 0, 1]

class sage.combinat.tableau.Tableau_class(parent, t, check=True)

This exists solely for unpickling Tableau_class objects.

class sage.combinat.tableau.Tableaux

A factory class for the various classes of tableaux.

INPUT:

• n (optional) – a non-negative integer

OUTPUT:

• If n is specified, the class of tableaux of size n. Otherwise, the class of all tableaux.

A tableau in Sage is a finite list of lists, whose lengths are weakly decreasing, or an empty list, representing the empty tableau. The entries of a tableau can be any Sage objects. Because of this, no enumeration through the set of Tableaux is possible.

EXAMPLES:

sage: T = Tableaux(); T
Tableaux
sage: T3 = Tableaux(3); T3
Tableaux of size 3
sage: [['a','b']] in T
True
sage: [['a','b']] in T3
False
sage: t = T3([[1,1,1]]); t
[[1, 1, 1]]
sage: t in T
True
sage: t.parent()
Tableaux of size 3
sage: T([]) # the empty tableau
[]
sage: T.category()
Category of sets

Element

alias of Tableau

options(*get_value, **set_value)

Sets the global options for elements of the tableau, skew_tableau, and tableau tuple classes. The defaults are for tableau to be displayed as a list, latexed as a Young diagram using the English convention.

OPTIONS:

• ascii_art – (default: repr) Controls the ascii art output for tableaux
• compact – minimal length ascii art
• repr – display using the diagram string representation
• table – display as a table
• convention – (default: English) Sets the convention used for displaying tableaux and partitions
• English – use the English convention
• French – use the French convention
• display – (default: list) Controls the way in which tableaux are printed
• array – alias for diagram
• compact – minimal length string representation
• diagram – display as Young diagram (similar to pp()
• ferrers_diagram – alias for diagram
• list – print tableaux as lists
• young_diagram – alias for diagram
• latex – (default: diagram) Controls the way in which tableaux are latexed
• array – alias for diagram
• diagram – as a Young diagram
• ferrers_diagram – alias for diagram
• list – as a list
• young_diagram – alias for diagram
• notation – alternative name for convention

Note

Changing the convention for tableaux also changes the convention for partitions.

If no parameters are set, then the function returns a copy of the options dictionary.

EXAMPLES:

sage: T = Tableau([[1,2,3],[4,5]])
sage: T
[[1, 2, 3], [4, 5]]
sage: Tableaux.options.display="array"
sage: T
1  2  3
4  5
sage: Tableaux.options.convention="french"
sage: T
4  5
1  2  3


Changing the convention for tableaux also changes the convention for partitions and vice versa:

sage: P = Partition([3,3,1])
sage: print(P.ferrers_diagram())
*
***
***
sage: Partitions.options.convention="english"
sage: print(P.ferrers_diagram())
***
***
*
sage: T
1  2  3
4  5


The ASCII art can also be changed:

sage: t = Tableau([[1,2,3],[4,5]])
sage: ascii_art(t)
1  2  3
4  5
sage: Tableaux.options.ascii_art = "table"
sage: ascii_art(t)
+---+---+---+
| 1 | 2 | 3 |
+---+---+---+
| 4 | 5 |
+---+---+
sage: Tableaux.options.ascii_art = "compact"
sage: ascii_art(t)
|1|2|3|
|4|5|
sage: Tableaux.options._reset()


See GlobalOptions for more features of these options.

class sage.combinat.tableau.Tableaux_all

Initializes the class of all tableaux

an_element()

Returns a particular element of the class.

class sage.combinat.tableau.Tableaux_size(n)

Tableaux of a fixed size $$n$$.

an_element()

Returns a particular element of the class.

sage.combinat.tableau.from_chain(chain)

Returns a semistandard tableau from a chain of partitions.

EXAMPLES:

sage: from sage.combinat.tableau import from_chain
sage: from_chain([[], , [2, 1], [3, 2, 1]])
[[1, 1, 3], [2, 3], ]

sage.combinat.tableau.from_shape_and_word(shape, w, convention='French')

Returns a tableau from a shape and word.

INPUT:

• shape – a partition
• w – a word whose length equals that of the partition
• convention – a string which can take values "French" or "English"; the default is "French"

OUTPUT:

A tableau, whose shape is shape and whose reading word is w. If the convention is specified as "French", the reading word is to be read starting from the top row in French convention (= the bottom row in English convention). If the convention is specified as "English", the reading word is to be read starting with the top row in English convention.

EXAMPLES:

sage: from sage.combinat.tableau import from_shape_and_word
sage: t = Tableau([[1, 3], , ])
sage: shape = t.shape(); shape
[2, 1, 1]
sage: word = t.to_word(); word
word: 4213
sage: from_shape_and_word(shape, word)
[[1, 3], , ]
sage: word = Word(flatten(t))
sage: from_shape_and_word(shape, word, convention = "English")
[[1, 3], , ]

sage.combinat.tableau.symmetric_group_action_on_values(word, perm)

Return the image of the word word under the Lascoux-Schuetzenberger action of the permutation perm.

See Tableau.symmetric_group_action_on_values() for the definition of the Lascoux-Schuetzenberger action on semistandard tableaux. The transformation that the reading word of the tableau undergoes in said definition is precisely the Lascoux-Schuetzenberger action on words.

EXAMPLES:

sage: from sage.combinat.tableau import symmetric_group_action_on_values
sage: symmetric_group_action_on_values([1,1,1],[1,3,2])
[1, 1, 1]
sage: symmetric_group_action_on_values([1,1,1],[2,1,3])
[2, 2, 2]
sage: symmetric_group_action_on_values([1,2,1],[2,1,3])
[2, 2, 1]
sage: symmetric_group_action_on_values([2,2,2],[2,1,3])
[1, 1, 1]
sage: symmetric_group_action_on_values([2,1,2],[2,1,3])
[2, 1, 1]
sage: symmetric_group_action_on_values([2,2,3,1,1,2,2,3],[1,3,2])
[2, 3, 3, 1, 1, 2, 3, 3]
sage: symmetric_group_action_on_values([2,1,1],[2,1])
[2, 1, 2]
sage: symmetric_group_action_on_values([2,2,1],[2,1])
[1, 2, 1]
sage: symmetric_group_action_on_values([1,2,1],[2,1])
[2, 2, 1]

sage.combinat.tableau.unmatched_places(w, open, close)

Given a word w and two letters open and close to be treated as opening and closing parentheses (respectively), return a pair (xs, ys) that encodes the positions of the unmatched parentheses after the standard parenthesis matching procedure is applied to w.

More precisely, xs will be the list of all i such that w[i] is an unmatched closing parenthesis, while ys will be the list of all i such that w[i] is an unmatched opening parenthesis. Both lists returned are in increasing order.

EXAMPLES:

sage: from sage.combinat.tableau import unmatched_places
sage: unmatched_places([2,2,2,1,1,1],2,1)
([], [])
sage: unmatched_places([1,1,1,2,2,2],2,1)
([0, 1, 2], [3, 4, 5])
sage: unmatched_places([], 2, 1)
([], [])
sage: unmatched_places([1,2,4,6,2,1,5,3],2,1)
(, )
sage: unmatched_places([2,2,1,2,4,6,2,1,5,3], 2, 1)
([], [0, 3])
sage: unmatched_places([3,1,1,1,2,1,2], 2, 1)
([1, 2, 3], )