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+\documentclass{article}
+\usepackage{axiom}
+\begin{document}
+\title{\$SPAD/src/algebra sgcf.spad}
+\author{Johannes Grabmeier, Thorsten Werther}
+\maketitle
+\begin{abstract}
+\end{abstract}
+\eject
+\tableofcontents
+\eject
+\section{package SGCF SymmetricGroupCombinatoricFunctions}
+<<package SGCF SymmetricGroupCombinatoricFunctions>>=
+)abbrev package SGCF SymmetricGroupCombinatoricFunctions
+++ Authors: Johannes Grabmeier, Thorsten Werther
+++ Date Created: 03 September 1988
+++ Date Last Updated: 07 June 1990
+++ Basic Operations: nextPartition, numberOfImproperPartitions,
+++ listYoungTableaus, subSet, unrankImproperPartitions0
+++ Related Constructors: IntegerCombinatoricFunctions
+++ Also See: RepresentationTheoryPackage1, RepresentationTheoryPackage2,
+++ IrrRepSymNatPackage
+++ AMS Classifications:
+++ Keywords: improper partition, partition, subset, Coleman
+++ References:
+++ G. James/ A. Kerber: The Representation Theory of the Symmetric
+++ Group. Encycl. of Math. and its Appl., Vol. 16., Cambridge
+++ Univ. Press 1981, ISBN 0-521-30236-6.
+++ S.G. Williamson: Combinatorics for Computer Science,
+++ Computer Science Press, Rockville, Maryland, USA, ISBN 0-88175-020-4.
+++ A. Nijenhuis / H.S. Wilf: Combinatoral Algorithms, Academic Press 1978.
+++ ISBN 0-12-519260-6.
+++ H. Gollan, J. Grabmeier: Algorithms in Representation Theory and
+++ their Realization in the Computer Algebra System Scratchpad,
+++ Bayreuther Mathematische Schriften, Heft 33, 1990, 1-23.
+++ Description:
+++ SymmetricGroupCombinatoricFunctions contains combinatoric
+++ functions concerning symmetric groups and representation
+++ theory: list young tableaus, improper partitions, subsets
+++ bijection of Coleman.
+
+SymmetricGroupCombinatoricFunctions(): public == private where
+
+ NNI ==> NonNegativeInteger
+ I ==> Integer
+ L ==> List
+ M ==> Matrix
+ V ==> Vector
+ B ==> Boolean
+ ICF ==> IntegerCombinatoricFunctions Integer
+
+ public ==> with
+
+-- IS THERE A WORKING DOMAIN Tableau ??
+-- coerce : M I -> Tableau(I)
+-- ++ coerce(ytab) coerces the Young-Tableau ytab to an element of
+-- ++ the domain Tableau(I).
+
+ coleman : (L I, L I, L I) -> M I
+ ++ coleman(alpha,beta,pi):
+ ++ there is a bijection from the set of matrices having nonnegative
+ ++ entries and row sums {\em alpha}, column sums {\em beta}
+ ++ to the set of {\em Salpha - Sbeta} double cosets of the
+ ++ symmetric group {\em Sn}. ({\em Salpha} is the Young subgroup
+ ++ corresponding to the improper partition {\em alpha}).
+ ++ For a representing element {\em pi} of such a double coset,
+ ++ coleman(alpha,beta,pi) generates the Coleman-matrix
+ ++ corresponding to {\em alpha, beta, pi}.
+ ++ Note: The permutation {\em pi} of {\em {1,2,...,n}} has to be given
+ ++ in list form.
+ ++ Note: the inverse of this map is {\em inverseColeman}
+ ++ (if {\em pi} is the lexicographical smallest permutation
+ ++ in the coset). For details see James/Kerber.
+ inverseColeman : (L I, L I, M I) -> L I
+ ++ inverseColeman(alpha,beta,C):
+ ++ there is a bijection from the set of matrices having nonnegative
+ ++ entries and row sums {\em alpha}, column sums {\em beta}
+ ++ to the set of {\em Salpha - Sbeta} double cosets of the
+ ++ symmetric group {\em Sn}. ({\em Salpha} is the Young subgroup
+ ++ corresponding to the improper partition {\em alpha}).
+ ++ For such a matrix C, inverseColeman(alpha,beta,C)
+ ++ calculates the lexicographical smallest {\em pi} in the
+ ++ corresponding double coset.
+ ++ Note: the resulting permutation {\em pi} of {\em {1,2,...,n}}
+ ++ is given in list form.
+ ++ Notes: the inverse of this map is {\em coleman}.
+ ++ For details, see James/Kerber.
+ listYoungTableaus : (L I) -> L M I
+ ++ listYoungTableaus(lambda) where {\em lambda} is a proper partition
+ ++ generates the list of all standard tableaus of shape {\em lambda}
+ ++ by means of lattice permutations. The numbers of the lattice
+ ++ permutation are interpreted as column labels. Hence the
+ ++ contents of these lattice permutations are the conjugate of
+ ++ {\em lambda}.
+ ++ Notes: the functions {\em nextLatticePermutation} and
+ ++ {\em makeYoungTableau} are used.
+ ++ The entries are from {\em 0,...,n-1}.
+ makeYoungTableau : (L I,L I) -> M I
+ ++ makeYoungTableau(lambda,gitter) computes for a given lattice
+ ++ permutation {\em gitter} and for an improper partition {\em lambda}
+ ++ the corresponding standard tableau of shape {\em lambda}.
+ ++ Notes: see {\em listYoungTableaus}.
+ ++ The entries are from {\em 0,...,n-1}.
+ nextColeman : (L I, L I, M I) -> M I
+ ++ nextColeman(alpha,beta,C) generates the next Coleman matrix
+ ++ of column sums {\em alpha} and row sums {\em beta} according
+ ++ to the lexicographical order from bottom-to-top.
+ ++ The first Coleman matrix is achieved by {\em C=new(1,1,0)}.
+ ++ Also, {\em new(1,1,0)} indicates that C is the last Coleman matrix.
+ nextLatticePermutation : (L I, L I, B) -> L I
+ ++ nextLatticePermutation(lambda,lattP,constructNotFirst) generates
+ ++ the lattice permutation according to the proper partition
+ ++ {\em lambda} succeeding the lattice permutation {\em lattP} in
+ ++ lexicographical order as long as {\em constructNotFirst} is true.
+ ++ If {\em constructNotFirst} is false, the first lattice permutation
+ ++ is returned.
+ ++ The result {\em nil} indicates that {\em lattP} has no successor.
+ nextPartition : (V I, V I, I) -> V I
+ ++ nextPartition(gamma,part,number) generates the partition of
+ ++ {\em number} which follows {\em part} according to the right-to-left
+ ++ lexicographical order. The partition has the property that
+ ++ its components do not exceed the corresponding components of
+ ++ {\em gamma}. The first partition is achieved by {\em part=[]}.
+ ++ Also, {\em []} indicates that {\em part} is the last partition.
+ nextPartition : (L I, V I, I) -> V I
+ ++ nextPartition(gamma,part,number) generates the partition of
+ ++ {\em number} which follows {\em part} according to the right-to-left
+ ++ lexicographical order. The partition has the property that
+ ++ its components do not exceed the corresponding components of
+ ++ {\em gamma}. the first partition is achieved by {\em part=[]}.
+ ++ Also, {\em []} indicates that {\em part} is the last partition.
+ numberOfImproperPartitions: (I,I) -> I
+ ++ numberOfImproperPartitions(n,m) computes the number of partitions
+ ++ of the nonnegative integer n in m nonnegative parts with regarding
+ ++ the order (improper partitions).
+ ++ Example: {\em numberOfImproperPartitions (3,3)} is 10,
+ ++ since {\em [0,0,3], [0,1,2], [0,2,1], [0,3,0], [1,0,2], [1,1,1],
+ ++ [1,2,0], [2,0,1], [2,1,0], [3,0,0]} are the possibilities.
+ ++ Note: this operation has a recursive implementation.
+ subSet : (I,I,I) -> L I
+ ++ subSet(n,m,k) calculates the {\em k}-th {\em m}-subset of the set
+ ++ {\em 0,1,...,(n-1)} in the lexicographic order considered as
+ ++ a decreasing map from {\em 0,...,(m-1)} into {\em 0,...,(n-1)}.
+ ++ See S.G. Williamson: Theorem 1.60.
+ ++ Error: if not {\em (0 <= m <= n and 0 < = k < (n choose m))}.
+ unrankImproperPartitions0 : (I,I,I) -> L I
+ ++ unrankImproperPartitions0(n,m,k) computes the {\em k}-th improper
+ ++ partition of nonnegative n in m nonnegative parts in reverse
+ ++ lexicographical order.
+ ++ Example: {\em [0,0,3] < [0,1,2] < [0,2,1] < [0,3,0] <
+ ++ [1,0,2] < [1,1,1] < [1,2,0] < [2,0,1] < [2,1,0] < [3,0,0]}.
+ ++ Error: if k is negative or too big.
+ ++ Note: counting of subtrees is done by
+ ++ \spadfunFrom{numberOfImproperPartitions}{SymmetricGroupCombinatoricFunctions}.
+
+ unrankImproperPartitions1: (I,I,I) -> L I
+ ++ unrankImproperPartitions1(n,m,k) computes the {\em k}-th improper
+ ++ partition of nonnegative n in at most m nonnegative parts
+ ++ ordered as follows: first, in reverse
+ ++ lexicographically according to their non-zero parts, then
+ ++ according to their positions (i.e. lexicographical order
+ ++ using {\em subSet}: {\em [3,0,0] < [0,3,0] < [0,0,3] < [2,1,0] <
+ ++ [2,0,1] < [0,2,1] < [1,2,0] < [1,0,2] < [0,1,2] < [1,1,1]}).
+ ++ Note: counting of subtrees is done by
+ ++ {\em numberOfImproperPartitionsInternal}.
+
+ private == add
+
+ import Set I
+
+ -- declaration of local functions
+
+
+ numberOfImproperPartitionsInternal: (I,I,I) -> I
+ -- this is used as subtree counting function in
+ -- "unrankImproperPartitions1". For (n,m,cm) it counts
+ -- the following set of m-tuples: The first (from left
+ -- to right) m-cm non-zero entries are equal, the remaining
+ -- positions sum up to n. Example: (3,3,2) counts
+ -- [x,3,0], [x,0,3], [0,x,3], [x,2,1], [x,1,2], x non-zero.
+
+
+ -- definition of local functions
+
+
+ numberOfImproperPartitionsInternal(n,m,cm) ==
+ n = 0 => binomial(m,cm)$ICF
+ cm = 0 and n > 0 => 0
+ s := 0
+ for i in 0..n-1 repeat
+ s := s + numberOfImproperPartitionsInternal(i,m,cm-1)
+ s
+
+
+ -- definition of exported functions
+
+ numberOfImproperPartitions(n,m) ==
+ if n < 0 or m < 1 then return 0
+ if m = 1 or n = 0 then return 1
+ s := 0
+ for i in 0..n repeat
+ s := s + numberOfImproperPartitions(n-i,m-1)
+ s
+
+
+ unrankImproperPartitions0(n,m,k) ==
+ l : L I := nil$(L I)
+ k < 0 => error"counting of partitions is started at 0"
+ k >= numberOfImproperPartitions(n,m) =>
+ error"there are not so many partitions"
+ for t in 0..(m-2) repeat
+ s : I := 0
+ for y in 0..n repeat
+ sOld := s
+ s := s + numberOfImproperPartitions(n-y,m-t-1)
+ if s > k then leave
+ l := append(l,list(y)$(L I))$(L I)
+ k := k - sOld
+ n := n - y
+ l := append(l,list(n)$(L I))$(L I)
+ l
+
+
+ unrankImproperPartitions1(n,m,k) ==
+ -- we use the counting procedure of the leaves in a tree
+ -- having the following structure: First of all non-zero
+ -- labels for the sons. If addition along a path gives n,
+ -- then we go on creating the subtree for (n choose cm)
+ -- where cm is the length of the path. These subsets determine
+ -- the positions for the non-zero labels for the partition
+ -- to be formeded. The remaining positions are filled by zeros.
+ nonZeros : L I := nil$(L I)
+ partition : V I := new(m::NNI,0$I)$(V I)
+ k < 0 => nonZeros
+ k >= numberOfImproperPartitions(n,m) => nonZeros
+ cm : I := m --cm gives the depth of the tree
+ while n ^= 0 repeat
+ s : I := 0
+ cm := cm - 1
+ for y in n..1 by -1 repeat --determination of the next son
+ sOld := s -- remember old s
+ -- this functions counts the number of elements in a subtree
+ s := s + numberOfImproperPartitionsInternal(n-y,m,cm)
+ if s > k then leave
+ -- y is the next son, so put it into the pathlist "nonZero"
+ nonZeros := append(nonZeros,list(y)$(L I))$(L I)
+ k := k - sOld --updating
+ n := n - y --updating
+ --having found all m-cm non-zero entries we change the structure
+ --of the tree and determine the non-zero positions
+ nonZeroPos : L I := reverse subSet(m,m-cm,k)
+ --building the partition
+ for i in 1..m-cm repeat partition.(1+nonZeroPos.i) := nonZeros.i
+ entries partition
+
+
+ subSet(n,m,k) ==
+ k < 0 or n < 0 or m < 0 or m > n =>
+ error "improper argument to subSet"
+ bin : I := binomial$ICF (n,m)
+ k >= bin =>
+ error "there are not so many subsets"
+ l : L I := []
+ n = 0 => l
+ mm : I := k
+ s : I := m
+ for t in 0..(m-1) repeat
+ for y in (s-1)..(n+1) repeat
+ if binomial$ICF (y,s) > mm then leave
+ l := append (l,list(y-1)$(L I))
+ mm := mm - binomial$ICF (y-1,s)
+ s := s-1
+ l
+
+
+ nextLatticePermutation(lambda, lattP, constructNotFirst) ==
+
+ lprime : L I := conjugate(lambda)$PartitionsAndPermutations
+ columns : NNI := (first(lambda)$(L I))::NNI
+ rows : NNI := (first(lprime)$(L I))::NNI
+ n : NNI :=(+/lambda)::NNI
+
+ not constructNotFirst => -- first lattice permutation
+ lattP := nil$(L I)
+ for i in columns..1 by -1 repeat
+ for l in 1..lprime(i) repeat
+ lattP := cons(i,lattP)
+ lattP
+
+ help : V I := new(columns,0) -- entry help(i) stores the number
+ -- of occurences of number i on our way from right to left
+ rightPosition : NNI := n
+ leftEntry : NNI := lattP(rightPosition)::NNI
+ ready : B := false
+ until (ready or (not constructNotFirst)) repeat
+ rightEntry : NNI := leftEntry
+ leftEntry := lattP(rightPosition-1)::NNI
+ help(rightEntry) := help(rightEntry) + 1
+ -- search backward decreasing neighbour elements
+ if rightEntry > leftEntry then
+ if ((lprime(leftEntry)-help(leftEntry)) >_
+ (lprime(rightEntry)-help(rightEntry)+1)) then
+ -- the elements may be swapped because the number of occurances
+ -- of leftEntry would still be greater than those of rightEntry
+ ready := true
+ j : NNI := leftEntry + 1
+ -- search among the numbers leftEntry+1..rightEntry for the
+ -- smallest one which can take the place of leftEntry.
+ -- negation of condition above:
+ while (help(j)=0) or ((lprime(leftEntry)-lprime(j))
+ < (help(leftEntry)-help(j)+2)) repeat j := j + 1
+ lattP(rightPosition-1) := j
+ help(j) := help(j)-1
+ help(leftEntry) := help(leftEntry) + 1
+ -- reconstruct the rest of the list in increasing order
+ for l in rightPosition..n repeat
+ j := 0
+ while help(1+j) = 0 repeat j := j + 1
+ lattP(l::NNI) := j+1
+ help(1+j) := help(1+j) - 1
+ -- end of "if rightEntry > leftEntry"
+ rightPosition := (rightPosition-1)::NNI
+ if rightPosition = 1 then constructNotFirst := false
+ -- end of repeat-loop
+ not constructNotFirst => nil$(L I)
+ lattP
+
+
+ makeYoungTableau(lambda,gitter) ==
+ lprime : L I := conjugate(lambda)$PartitionsAndPermutations
+ columns : NNI := (first(lambda)$(L I))::NNI
+ rows : NNI := (first(lprime)$(L I))::NNI
+ ytab : M I := new(rows,columns,0)
+ help : V I := new(columns,1)
+ i : I := -1 -- this makes the entries ranging from 0,..,n-1
+ -- i := 0 would make it from 1,..,n.
+ j : I := 0
+ for l in 1..maxIndex gitter repeat
+ j := gitter(l)
+ i := i + 1
+ ytab(help(j),j) := i
+ help(j) := help(j) + 1
+ ytab
+
+
+-- coerce(ytab) ==
+-- lli := listOfLists(ytab)$(M I)
+-- -- remove the filling zeros in each row. It is assumed that
+-- -- that there are no such in row 0.
+-- for i in 2..maxIndex lli repeat
+-- THIS IS DEFINIVELY WRONG, I NEED A FUNCTION WHICH DELETES THE
+-- 0s, in my version there are no mapping facilities yet.
+-- deleteInPlace(not zero?,lli i)
+-- tableau(lli)$Tableau(I)
+
+
+ listYoungTableaus(lambda) ==
+ lattice : L I
+ ytab : M I
+ younglist : L M I := nil$(L M I)
+ lattice := nextLatticePermutation(lambda,lattice,false)
+ until null lattice repeat
+ ytab := makeYoungTableau(lambda,lattice)
+ younglist := append(younglist,[ytab]$(L M I))$(L M I)
+ lattice := nextLatticePermutation(lambda,lattice,true)
+ younglist
+
+
+ nextColeman(alpha,beta,C) ==
+ nrow : NNI := #beta
+ ncol : NNI := #alpha
+ vnull : V I := vector(nil()$(L I)) -- empty vector
+ vzero : V I := new(ncol,0)
+ vrest : V I := new(ncol,0)
+ cnull : M I := new(1,1,0)
+ coleman := copy C
+ if coleman ^= cnull then
+ -- look for the first row of "coleman" that has a succeeding
+ -- partition, this can be atmost row nrow-1
+ i : NNI := (nrow-1)::NNI
+ vrest := row(coleman,i) + row(coleman,nrow)
+ --for k in 1..ncol repeat
+ -- vrest(k) := coleman(i,k) + coleman(nrow,k)
+ succ := nextPartition(vrest,row(coleman, i),beta(i))
+ while (succ = vnull) repeat
+ if i = 1 then return cnull -- part is last partition
+ i := (i - 1)::NNI
+ --for k in 1..ncol repeat
+ -- vrest(k) := vrest(k) + coleman(i,k)
+ vrest := vrest + row(coleman,i)
+ succ := nextPartition(vrest, row(coleman, i), beta(i))
+ j : I := i
+ coleman := setRow_!(coleman, i, succ)
+ --for k in 1..ncol repeat
+ -- vrest(k) := vrest(k) - coleman(i,k)
+ vrest := vrest - row(coleman,i)
+ else
+ vrest := vector alpha
+ -- for k in 1..ncol repeat
+ -- vrest(k) := alpha(k)
+ coleman := new(nrow,ncol,0)
+ j : I := 0
+ for i in (j+1)::NNI..nrow-1 repeat
+ succ := nextPartition(vrest,vnull,beta(i))
+ coleman := setRow_!(coleman, i, succ)
+ vrest := vrest - succ
+ --for k in 1..ncol repeat
+ -- vrest(k) := vrest(k) - succ(k)
+ setRow_!(coleman, nrow, vrest)
+
+
+ nextPartition(gamma:V I, part:V I, number:I) ==
+ nextPartition(entries gamma, part, number)
+
+
+ nextPartition(gamma:L I,part:V I,number:I) ==
+ n : NNI := #gamma
+ vnull : V I := vector(nil()$(L I)) -- empty vector
+ if part ^= vnull then
+ i : NNI := 2
+ sum := part(1)
+ while (part(i) = gamma(i)) or (sum = 0) repeat
+ sum := sum + part(i)
+ i := i + 1
+ if i = 1+n then return vnull -- part is last partition
+ sum := sum - 1
+ part(i) := part(i) + 1
+ else
+ sum := number
+ part := new(n,0)
+ i := 1+n
+ j : NNI := 1
+ while sum > gamma(j) repeat
+ part(j) := gamma(j)
+ sum := sum - gamma(j)
+ j := j + 1
+ part(j) := sum
+ for k in j+1..i-1 repeat
+ part(k) := 0
+ part
+
+
+ inverseColeman(alpha,beta,C) ==
+ pi : L I := nil$(L I)
+ nrow : NNI := #beta
+ ncol : NNI := #alpha
+ help : V I := new(nrow,0)
+ sum : I := 1
+ for i in 1..nrow repeat
+ help(i) := sum
+ sum := sum + beta(i)
+ for j in 1..ncol repeat
+ for i in 1..nrow repeat
+ for k in 2..1+C(i,j) repeat
+ pi := append(pi,list(help(i))$(L I))
+ help(i) := help(i) + 1
+ pi
+
+
+ coleman(alpha,beta,pi) ==
+ nrow : NNI := #beta
+ ncol : NNI := #alpha
+ temp : L L I := nil$(L L I)
+ help : L I := nil$(L I)
+ colematrix : M I := new(nrow,ncol,0)
+ betasum : NNI := 0
+ alphasum : NNI := 0
+ for i in 1..ncol repeat
+ help := nil$(L I)
+ for j in alpha(i)..1 by-1 repeat
+ help := cons(pi(j::NNI+alphasum),help)
+ alphasum := (alphasum + alpha(i))::NNI
+ temp := append(temp,list(help)$(L L I))
+ for i in 1..nrow repeat
+ help := nil$(L I)
+ for j in beta(i)..1 by-1 repeat
+ help := cons(j::NNI+betasum, help)
+ betasum := (betasum + beta(i))::NNI
+ for j in 1..ncol repeat
+ colematrix(i,j) := #intersect(brace(help),brace(temp(j)))
+ colematrix
+
+@
+\section{License}
+<<license>>=
+--Copyright (c) 1991-2002, The Numerical ALgorithms Group Ltd.
+--All rights reserved.
+--
+--Redistribution and use in source and binary forms, with or without
+--modification, are permitted provided that the following conditions are
+--met:
+--
+-- - Redistributions of source code must retain the above copyright
+-- notice, this list of conditions and the following disclaimer.
+--
+-- - Redistributions in binary form must reproduce the above copyright
+-- notice, this list of conditions and the following disclaimer in
+-- the documentation and/or other materials provided with the
+-- distribution.
+--
+-- - Neither the name of The Numerical ALgorithms Group Ltd. nor the
+-- names of its contributors may be used to endorse or promote products
+-- derived from this software without specific prior written permission.
+--
+--THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+--IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+--TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+--PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+--OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+--EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+--PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+--PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+--LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+--NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+--SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+@
+<<*>>=
+<<license>>
+
+<<package SGCF SymmetricGroupCombinatoricFunctions>>
+@
+\eject
+\begin{thebibliography}{99}
+\bibitem{1} nothing
+\end{thebibliography}
+\end{document}