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GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
Project: cocalc-sagemath-dev-slelievre
Views: 418346#############################################################################
##
## ResidueClassRingTools.gi MatricesForHomalg package Mohamed Barakat
##
## Copyright 2007-2009 Mohamed Barakat, Universität des Saarlandes
##
## Implementation stuff for homalg residue class rings.
##
#############################################################################
####################################
#
# global variables:
#
####################################
##
InstallValue( CommonHomalgTableForResidueClassRingsTools,
rec(
IsZero := r -> IsZero( DecideZero( EvalRingElement( r ), HomalgRing( r ) ) ),
IsOne := r -> IsOne( DecideZero( EvalRingElement( r ), HomalgRing( r ) ) ),
Minus :=
function( a, b )
return DecideZero( EvalRingElement( a ) - EvalRingElement( b ), HomalgRing( a ) );
end,
DivideByUnit :=
function( a, u )
local R, S, A, U, rel, au;
R := HomalgRing( a );
S := AmbientRing( R );
A := HomalgMatrix( [ EvalRingElement( a ) ], 1, 1, S );
U := HomalgMatrix( [ EvalRingElement( u ) ], 1, 1, S );
rel := RingRelations( R );
rel := MatrixOfRelations( rel );
if IsHomalgRingRelationsAsGeneratorsOfRightIdeal( rel ) then
rel := Involution( rel ); ## I prefer row convention
fi;
au := RightDivide( A, U, rel );
if au = fail then
return fail;
fi;
au := MatElm( au, 1, 1 );
au := DecideZero( au, HomalgRing( a ) );
return au;
end,
IsUnit :=
function( R, u )
local U;
U := HomalgMatrix( [ EvalRingElement( u ) ], 1, 1, AmbientRing( R ) );
U := HomalgResidueClassMatrix( U, R );
return not IsBool( LeftInverse( U ) );
end,
Sum :=
function( a, b )
return DecideZero( EvalRingElement( a ) + EvalRingElement( b ), HomalgRing( a ) );
end,
Product :=
function( a, b )
return DecideZero( EvalRingElement( a ) * EvalRingElement( b ), HomalgRing( a ) );
end,
ShallowCopy :=
function( C )
local M;
M := ShallowCopy( Eval( C ) );
if not ( HasIsReducedModuloRingRelations( C ) and
IsReducedModuloRingRelations( C ) ) then
## reduce the matrix N w.r.t. the ring relations
M := DecideZero( M, HomalgRing( C ) );
fi;
return M;
end,
CopyMatrix :=
function( C, R )
return R * Eval( C );
end,
## <#GAPDoc Label="InitialMatrix:ResidueClassRing">
## <ManSection>
## <Func Arg="" Name="InitialMatrix" Label="ResidueClassRing"/>
## <Returns>a &homalg; matrix over the ambient ring</Returns>
## <Description>
## (&see; <Ref Meth="InitialMatrix" Label="homalgTable entry for initial matrices"/>)
## <Listing Type="Code"><![CDATA[
InitialMatrix := C -> HomalgInitialMatrix(
NrRows( C ), NrColumns( C ), AmbientRing( HomalgRing( C ) ) ),
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="InitialIdentityMatrix:ResidueClassRing">
## <ManSection>
## <Func Arg="" Name="InitialIdentityMatrix" Label="ResidueClassRing"/>
## <Returns>a &homalg; matrix over the ambient ring</Returns>
## <Description>
## (&see; <Ref Meth="InitialIdentityMatrix" Label="homalgTable entry for initial identity matrices"/>)
## <Listing Type="Code"><![CDATA[
InitialIdentityMatrix := C -> HomalgInitialIdentityMatrix(
NrRows( C ), AmbientRing( HomalgRing( C ) ) ),
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="ZeroMatrix:ResidueClassRing">
## <ManSection>
## <Func Arg="" Name="ZeroMatrix" Label="ResidueClassRing"/>
## <Returns>a &homalg; matrix over the ambient ring</Returns>
## <Description>
## (&see; <Ref Meth="ZeroMatrix" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
ZeroMatrix := C -> HomalgZeroMatrix(
NrRows( C ), NrColumns( C ), AmbientRing( HomalgRing( C ) ) ),
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="IdentityMatrix:ResidueClassRing">
## <ManSection>
## <Func Arg="" Name="IdentityMatrix" Label="ResidueClassRing"/>
## <Returns>a &homalg; matrix over the ambient ring</Returns>
## <Description>
## (&see; <Ref Meth="IdentityMatrix" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
IdentityMatrix := C -> HomalgIdentityMatrix(
NrRows( C ), AmbientRing( HomalgRing( C ) ) ),
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="AreEqualMatrices:ResidueClassRing">
## <ManSection>
## <Func Arg="A, B" Name="AreEqualMatrices" Label="ResidueClassRing"/>
## <Returns><C>true</C> or <C>false</C></Returns>
## <Description>
## (&see; <Ref Meth="AreEqualMatrices" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
AreEqualMatrices :=
function( A, B )
return IsZero( DecideZero( Eval( A ) - Eval( B ), HomalgRing( A ) ) );
end,
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="Involution:ResidueClassRing">
## <ManSection>
## <Func Arg="" Name="Involution" Label="ResidueClassRing"/>
## <Returns>a &homalg; matrix over the ambient ring</Returns>
## <Description>
## (&see; <Ref Meth="Involution" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
Involution :=
function( M )
local N, R;
N := Involution( Eval( M ) );
R := HomalgRing( N );
if not ( HasIsCommutative( R ) and IsCommutative( R ) and
HasIsReducedModuloRingRelations( M ) and
IsReducedModuloRingRelations( M ) ) then
## reduce the matrix N w.r.t. the ring relations
N := DecideZero( N, HomalgRing( M ) );
fi;
return N;
end,
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="CertainRows:ResidueClassRing">
## <ManSection>
## <Func Arg="" Name="CertainRows" Label="ResidueClassRing"/>
## <Returns>a &homalg; matrix over the ambient ring</Returns>
## <Description>
## (&see; <Ref Meth="CertainRows" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
CertainRows :=
function( M, plist )
local N;
N := CertainRows( Eval( M ), plist );
if not ( HasIsReducedModuloRingRelations( M ) and
IsReducedModuloRingRelations( M ) ) then
## reduce the matrix N w.r.t. the ring relations
N := DecideZero( N, HomalgRing( M ) );
fi;
return N;
end,
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="CertainColumns:ResidueClassRing">
## <ManSection>
## <Func Arg="" Name="CertainColumns" Label="ResidueClassRing"/>
## <Returns>a &homalg; matrix over the ambient ring</Returns>
## <Description>
## (&see; <Ref Meth="CertainColumns" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
CertainColumns :=
function( M, plist )
local N;
N := CertainColumns( Eval( M ), plist );
if not ( HasIsReducedModuloRingRelations( M ) and
IsReducedModuloRingRelations( M ) ) then
## reduce the matrix N w.r.t. the ring relations
N := DecideZero( N, HomalgRing( M ) );
fi;
return N;
end,
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="UnionOfRows:ResidueClassRing">
## <ManSection>
## <Func Arg="" Name="UnionOfRows" Label="ResidueClassRing"/>
## <Returns>a &homalg; matrix over the ambient ring</Returns>
## <Description>
## (&see; <Ref Meth="UnionOfRows" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
UnionOfRows :=
function( A, B )
local N;
N := UnionOfRows( Eval( A ), Eval( B ) );
if not ForAll( [ A, B ], HasIsReducedModuloRingRelations and
IsReducedModuloRingRelations ) then
## reduce the matrix N w.r.t. the ring relations
N := DecideZero( N, HomalgRing( A ) );
fi;
return N;
end,
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="UnionOfColumns:ResidueClassRing">
## <ManSection>
## <Func Arg="" Name="UnionOfColumns" Label="ResidueClassRing"/>
## <Returns>a &homalg; matrix over the ambient ring</Returns>
## <Description>
## (&see; <Ref Meth="UnionOfColumns" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
UnionOfColumns :=
function( A, B )
local N;
N := UnionOfColumns( Eval( A ), Eval( B ) );
if not ForAll( [ A, B ], HasIsReducedModuloRingRelations and
IsReducedModuloRingRelations ) then
## reduce the matrix N w.r.t. the ring relations
N := DecideZero( N, HomalgRing( A ) );
fi;
return N;
end,
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="DiagMat:ResidueClassRing">
## <ManSection>
## <Func Arg="" Name="DiagMat" Label="ResidueClassRing"/>
## <Returns>a &homalg; matrix over the ambient ring</Returns>
## <Description>
## (&see; <Ref Meth="DiagMat" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
DiagMat :=
function( e )
local N;
N := DiagMat( List( e, Eval ) );
if not ForAll( e, HasIsReducedModuloRingRelations and
IsReducedModuloRingRelations ) then
## reduce the matrix N w.r.t. the ring relations
N := DecideZero( N, HomalgRing( e[1] ) );
fi;
return N;
end,
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="KroneckerMat:ResidueClassRing">
## <ManSection>
## <Func Arg="" Name="KroneckerMat" Label="ResidueClassRing"/>
## <Returns>a &homalg; matrix over the ambient ring</Returns>
## <Description>
## (&see; <Ref Meth="KroneckerMat" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
KroneckerMat :=
function( A, B )
local N;
N := KroneckerMat( Eval( A ), Eval( B ) );
if not ForAll( [ A, B ], HasIsReducedModuloRingRelations and
IsReducedModuloRingRelations ) then
## reduce the matrix N w.r.t. the ring relations
N := DecideZero( N, HomalgRing( A ) );
fi;
return N;
end,
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="MulMat:ResidueClassRing">
## <ManSection>
## <Func Arg="" Name="MulMat" Label="ResidueClassRing"/>
## <Returns>a &homalg; matrix over the ambient ring</Returns>
## <Description>
## (&see; <Ref Meth="MulMat" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
MulMat :=
function( a, A )
return DecideZero( EvalRingElement( a ) * Eval( A ), HomalgRing( A ) );
end,
MulMatRight :=
function( A, a )
return DecideZero( Eval( A ) * EvalRingElement( a ), HomalgRing( A ) );
end,
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="AddMat:ResidueClassRing">
## <ManSection>
## <Func Arg="" Name="AddMat" Label="ResidueClassRing"/>
## <Returns>a &homalg; matrix over the ambient ring</Returns>
## <Description>
## (&see; <Ref Meth="AddMat" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
AddMat :=
function( A, B )
return DecideZero( Eval( A ) + Eval( B ), HomalgRing( A ) );
end,
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="SubMat:ResidueClassRing">
## <ManSection>
## <Func Arg="" Name="SubMat" Label="ResidueClassRing"/>
## <Returns>a &homalg; matrix over the ambient ring</Returns>
## <Description>
## (&see; <Ref Meth="SubMat" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
SubMat :=
function( A, B )
return DecideZero( Eval( A ) - Eval( B ), HomalgRing( A ) );
end,
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="Compose:ResidueClassRing">
## <ManSection>
## <Func Arg="" Name="Compose" Label="ResidueClassRing"/>
## <Returns>a &homalg; matrix over the ambient ring</Returns>
## <Description>
## (&see; <Ref Meth="Compose" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
Compose :=
function( A, B )
return DecideZero( Eval( A ) * Eval( B ), HomalgRing( A ) );
end,
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="NrRows:ResidueClassRing">
## <ManSection>
## <Func Arg="C" Name="NrRows" Label="ResidueClassRing"/>
## <Returns>a nonnegative integer</Returns>
## <Description>
## (&see; <Ref Meth="NrRows" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
NrRows := C -> NrRows( Eval( C ) ),
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="NrColumns:ResidueClassRing">
## <ManSection>
## <Func Arg="C" Name="NrColumns" Label="ResidueClassRing"/>
## <Returns>a nonnegative integer</Returns>
## <Description>
## (&see; <Ref Meth="NrColumns" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
NrColumns := C -> NrColumns( Eval( C ) ),
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="Determinant:ResidueClassRing">
## <ManSection>
## <Func Arg="C" Name="Determinant" Label="ResidueClassRing"/>
## <Returns>an element of ambient &homalg; ring</Returns>
## <Description>
## (&see; <Ref Meth="Determinant" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
Determinant := C -> DecideZero( Determinant( Eval( C ) ), HomalgRing( C ) ),
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="IsZeroMatrix:ResidueClassRing">
## <ManSection>
## <Func Arg="M" Name="IsZeroMatrix" Label="ResidueClassRing"/>
## <Returns><C>true</C> or <C>false</C></Returns>
## <Description>
## (&see; <Ref Meth="IsZeroMatrix" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
IsZeroMatrix := M -> IsZero( DecideZero( Eval( M ), HomalgRing( M ) ) ),
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="IsIdentityMatrix:ResidueClassRing">
## <ManSection>
## <Func Arg="M" Name="IsOne" Label="ResidueClassRing"/>
## <Returns><C>true</C> or <C>false</C></Returns>
## <Description>
## (&see; <Ref Meth="IsIdentityMatrix" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
IsIdentityMatrix := M ->
IsOne( DecideZero( Eval( M ), HomalgRing( M ) ) ),
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="IsDiagonalMatrix:ResidueClassRing">
## <ManSection>
## <Func Arg="M" Name="IsDiagonalMatrix" Label="ResidueClassRing"/>
## <Returns><C>true</C> or <C>false</C></Returns>
## <Description>
## (&see; <Ref Meth="IsDiagonalMatrix" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
IsDiagonalMatrix := M ->
IsDiagonalMatrix( DecideZero( Eval( M ), HomalgRing( M ) ) ),
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="ZeroRows:ResidueClassRing">
## <ManSection>
## <Func Arg="C" Name="ZeroRows" Label="ResidueClassRing"/>
## <Returns>a &homalg; matrix over the ambient ring</Returns>
## <Description>
## (&see; <Ref Meth="ZeroRows" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
ZeroRows := C -> ZeroRows( DecideZero( Eval( C ), HomalgRing( C ) ) ),
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
## <#GAPDoc Label="ZeroColumns:ResidueClassRing">
## <ManSection>
## <Func Arg="C" Name="ZeroColumns" Label="ResidueClassRing"/>
## <Returns>a &homalg; matrix over the ambient ring</Returns>
## <Description>
## (&see; <Ref Meth="ZeroColumns" Label="homalgTable entry"/>)
## <Listing Type="Code"><![CDATA[
ZeroColumns := C -> ZeroColumns( DecideZero( Eval( C ), HomalgRing( C ) ) ),
## ]]></Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
Diff :=
function( D, N )
return HomalgRing( D ) * Diff( Eval( D ), Eval( N ) );
end,
X_CopyRowToIdentityMatrix :=
function( M, i, L, j )
end,
X_CopyColumnToIdentityMatrix :=
function( M, j, L, i )
end,
X_SetColumnToZero :=
function( M, i, j )
end,
X_GetCleanRowsPositions :=
function( M, clean_columns )
end,
Pullback :=
function( phi, M )
if not IsBound( phi!.RingMapToFree ) then
phi!.RingMapToFree := RingMap( ImagesOfRingMap( phi ), Source( phi ), AmbientRing( Range( phi ) ) );
fi;
return Pullback( phi!.RingMapToFree, M );
end,
)
);