resolves #1744

Bump ModulePresentationsForCAP to v2025.06-01

Author: kamalsaleh

ModulePresentationsForCAP/PackageInfo.g

@@ -10,7 +10,7 @@ SetPackageInfo( rec(
 
 PackageName := "ModulePresentationsForCAP",
 Subtitle := "Category R-pres for CAP",
-Version := "2024.09-02",
+Version := "2025.06-01",
 Date := (function ( ) if IsBound( GAPInfo.SystemEnvironment.GAP_PKG_RELEASE_DATE ) then return GAPInfo.SystemEnvironment.GAP_PKG_RELEASE_DATE; else return Concatenation( ~.Version{[ 1 .. 4 ]}, "-", ~.Version{[ 6, 7 ]}, "-01" ); fi; end)( ),
 License := "GPL-2.0-or-later",
 

ModulePresentationsForCAP/gap/ModulePresentationsForCAP.gi

@@ -1088,29 +1088,20 @@ InstallGlobalFunction( ADD_LIFT_AND_COLIFT_LEFT,
     M := UnderlyingMatrix( Source( morphism_2 ) );
 
     v := NrColumns( M );
-       
+    
     s := NrColumns( P );
 
     N := UnderlyingMatrix( Range(  morphism_1 ) );
 
-    # NrColumns( N ) = 0 implies coker(N)=0 and  s = 0 implies coker(P)=0, hence morphism_1 is zero, and the zero morphism can always be lifted. 
-    if NrColumns( N ) = 0 or s = 0 then
-        return ZeroMorphism( Source( morphism_1 ), Source( morphism_2 ) ); 
-    fi;
-    
-    # if NrColumns(M)=0 then M is zero, hence lift exists iff morphism_1 is zero.
-    if NrColumns( M ) = 0 and IsZeroForMorphisms( morphism_1 ) then
-        return ZeroMorphism( Source( morphism_1 ), Source( morphism_2 ) );
-    fi;
     A := UnderlyingMatrix( morphism_1 );
 
     B := UnderlyingMatrix( morphism_2 );
 
-    B_tr_I := KroneckerMat( TransposedMatrix( B ), HomalgIdentityMatrix( NrColumns( P ), homalg_ring ) );
+    B_tr_I := KroneckerMat( TransposedMatrix( B ), HomalgIdentityMatrix( NrColumns( P ), homalg_ring ) ); # ns x vs
 
-    N_tr_I := KroneckerMat( TransposedMatrix( N ), HomalgIdentityMatrix( NrColumns( P ) ,homalg_ring ) );
+    N_tr_I := KroneckerMat( TransposedMatrix( N ), HomalgIdentityMatrix( NrColumns( P ) ,homalg_ring ) ); # ns x ms
 
-    zero_1  := HomalgZeroMatrix( NrRows( A )*NrColumns( A ), NrRows( P )*NrRows( M ), homalg_ring );
+    zero_1  := HomalgZeroMatrix( NrRows( A )*NrColumns( A ), NrRows( P )*NrRows( M ), homalg_ring ); # ns x ru
 
     mat1 := UnionOfColumns( B_tr_I, N_tr_I, zero_1 );
 
@@ -1124,17 +1115,9 @@ InstallGlobalFunction( ADD_LIFT_AND_COLIFT_LEFT,
 
     mat := UnionOfRows( mat1, mat2 );
 
-    if NrColumns( A ) <= 1 then
-       
-       vec_A := A;
-       
-    else
-       
-       vec_A := UnionOfRows( List( [ 1 .. NrColumns( A ) ], i-> CertainColumns( A, [ i ] ) ) );
-       
-    fi;
+    vec_A := ConvertMatrixToColumn( A );
 
-    vec_zero := HomalgZeroMatrix( NrRows( P )*NrColumns( M ), 1, homalg_ring );
+    vec_zero := HomalgZeroMatrix( NrRows( P )*NrColumns( M ), NrColumns( vec_A ), homalg_ring );
 
     vec := UnionOfRows( vec_A, vec_zero );
 
@@ -1155,11 +1138,7 @@ InstallGlobalFunction( ADD_LIFT_AND_COLIFT_LEFT,
 
     sol := CallFuncList( LeftDivide, lift_via_compiled_linear_system_func( morphism_1, morphism_2 ) );
 
-    if v <= 1 then
-        XX := CertainRows( sol, [ 1.. s ] );
-    else
-        XX := UnionOfColumns( List( [ 1 .. v ], i-> CertainRows( sol, [ (i-1)*s+1.. i*s ] ) ) );
-    fi;
+    XX := UnionOfColumns( homalg_ring, s, List( [ 1 .. v ], i-> CertainRows( sol, [ (i-1)*s+1.. i*s ] ) ) );
 
     return PresentationMorphism( cat, Source( morphism_1 ), XX, Source( morphism_2 ) );
 
@@ -1195,21 +1174,11 @@ InstallGlobalFunction( ADD_LIFT_AND_COLIFT_LEFT,
     M := UnderlyingMatrix( Range( morphism_1 ) );
 
     v := NrColumns( M );
-       
+    
     s := NrColumns( I );
 
     N := UnderlyingMatrix( Source( morphism_1 ) );
 
-    # NrColumns( N ) = 0 implies coker(N)=0 and  s = 0 implies coker(I)=0, hence morphism_2 is zero, and the zero morphism can always be colifted.
-    if NrColumns( N ) = 0 or s = 0 then
-        return ZeroMorphism( Range( morphism_1 ), Range( morphism_2 ) );
-    fi;
-
-    # if NrColumns(M)=0 then M is zero, hence colift exists iff morphism_2 is zero.
-    if NrColumns( M ) = 0 and IsZeroForMorphisms( morphism_2 ) then
-        return ZeroMorphism( Range( morphism_1 ), Range( morphism_2 ) );
-    fi;
-
     B := UnderlyingMatrix( morphism_1 );
 
     A := UnderlyingMatrix( morphism_2 );
@@ -1226,12 +1195,8 @@ InstallGlobalFunction( ADD_LIFT_AND_COLIFT_LEFT,
 
     A_over_zero := UnionOfRows( A, zero_mat );
 
-    if NrColumns( A ) <= 1 then
-        vec := A_over_zero;
-    else
-        vec := UnionOfRows( List( [ 1 .. NrColumns( A ) ], i-> CertainColumns( A_over_zero, [ i ] ) ) );
-    fi;
-
+    vec := ConvertMatrixToColumn( A );
+    
     return [ mat, vec ];
 
   end;
@@ -1253,11 +1218,7 @@ InstallGlobalFunction( ADD_LIFT_AND_COLIFT_LEFT,
 
     s := NrColumns( I );
 
-    if s <= 1 then
-        XX := CertainRows( sol, [ 1.. v ] );
-    else
-        XX := UnionOfColumns( List( [ 1 .. s ], i-> CertainRows( sol, [ (i-1)*v+1.. i*v ] ) ) );
-    fi;
+    XX := UnionOfColumns( homalg_ring, v, List( [ 1 .. s ], i-> CertainRows( sol, [ (i-1)*v+1.. i*v ] ) ) );
 
     return PresentationMorphism( cat, Range( morphism_1 ), XX, Range( morphism_2 ) );
 
@@ -1314,14 +1275,6 @@ InstallGlobalFunction( ADD_LIFT_AND_COLIFT_RIGHT,
 
     Nt := TransposedMatrix( UnderlyingMatrix( Range(  morphism_1 ) ) );
 
-    if NrRows( Nt ) = 0 or s = 0 then
-        return ZeroMorphism( Source( morphism_1 ), Source( morphism_2 ) ); 
-    fi;
-
-    if NrRows( Mt ) = 0 and IsZeroForMorphisms( morphism_1 ) then
-        return ZeroMorphism( Source( morphism_1 ), Source( morphism_2 ) );
-    fi;
-
     At := TransposedMatrix( UnderlyingMatrix( morphism_1 ) );
 
     Bt := TransposedMatrix( UnderlyingMatrix( morphism_2 ) );
@@ -1344,17 +1297,9 @@ InstallGlobalFunction( ADD_LIFT_AND_COLIFT_RIGHT,
 
     mat := UnionOfRows( mat1, mat2 );
 
-    if NrColumns( At ) <= 1 then
-       
-       vec_A := At;
-       
-    else
-       
-       vec_A := UnionOfRows( List( [ 1 .. NrColumns( At ) ], i-> CertainColumns( At, [ i ] ) ) );
-       
-    fi;
+    vec_A := ConvertMatrixToColumn( At );
 
-    vec_zero := HomalgZeroMatrix( NrRows( Pt )*NrColumns( Mt ), 1, homalg_ring );
+    vec_zero := HomalgZeroMatrix( NrRows( Pt )*NrColumns( Mt ), NrColumns( vec_A ), homalg_ring );
 
     vec := UnionOfRows( vec_A, vec_zero );
 
@@ -1374,11 +1319,7 @@ InstallGlobalFunction( ADD_LIFT_AND_COLIFT_RIGHT,
 
     sol := CallFuncList( LeftDivide, lift_via_compiled_linear_system_func( morphism_1, morphism_2 ) );
 
-    if v <= 1 then
-        XX := TransposedMatrix( CertainRows( sol, [ 1.. s ] ) );
-    else
-        XX := TransposedMatrix( UnionOfColumns( List( [ 1 .. v ], i-> CertainRows( sol, [ (i-1)*s+1.. i*s ] ) ) ) );
-    fi;
+    XX := TransposedMatrix( UnionOfColumns( homalg_ring, s, List( [ 1 .. v ], i-> CertainRows( sol, [ (i-1)*s+1.. i*s ] ) ) ) );
 
     return PresentationMorphism( cat, Source( morphism_1 ), XX, Source( morphism_2 ) );
 
@@ -1398,19 +1339,11 @@ InstallGlobalFunction( ADD_LIFT_AND_COLIFT_RIGHT,
     Mt := TransposedMatrix( UnderlyingMatrix( Range( morphism_1 ) ) );
 
     v := NrColumns( Mt );
-       
+    
     s := NrColumns( It );
-        
-    Nt := TransposedMatrix( UnderlyingMatrix( Source( morphism_1 ) ) );
 
-    if NrRows( Nt ) = 0 or s = 0 then
-        return ZeroMorphism( Range( morphism_1 ), Range( morphism_2 ) );
-    fi;
+    Nt := TransposedMatrix( UnderlyingMatrix( Source( morphism_1 ) ) );
 
-    if NrRows( Mt ) = 0 and IsZeroForMorphisms( morphism_2 ) then
-        return ZeroMorphism( Range( morphism_1 ), Range( morphism_2 ) );
-    fi;
-
     Bt := TransposedMatrix( UnderlyingMatrix( morphism_1 ) );
 
     At := TransposedMatrix( UnderlyingMatrix( morphism_2 ) );
@@ -1427,12 +1360,8 @@ InstallGlobalFunction( ADD_LIFT_AND_COLIFT_RIGHT,
 
     A_over_zero := UnionOfRows( At, zero_mat );
 
-    if NrColumns( At ) <= 1 then
-        vec := A_over_zero;
-    else
-        vec := UnionOfRows( List( [ 1 .. NrColumns( At ) ], i-> CertainColumns( A_over_zero, [ i ] ) ) );
-    fi;
-
+    vec := ConvertMatrixToColumn( A_over_zero );
+    
     return [ mat, vec ];
 
   end;
@@ -1454,11 +1383,7 @@ InstallGlobalFunction( ADD_LIFT_AND_COLIFT_RIGHT,
 
     s := NrColumns( It );
 
-    if s <= 1 then
-        XX := TransposedMatrix( CertainRows( sol, [ 1.. v ] ) );
-    else
-        XX := TransposedMatrix( UnionOfColumns( List( [ 1 .. s ], i-> CertainRows( sol, [ (i-1)*v+1.. i*v ] ) ) ) );
-    fi;
+    XX := TransposedMatrix( UnionOfColumns( homalg_ring, v, List( [ 1 .. s ], i-> CertainRows( sol, [ (i-1)*v+1.. i*v ] ) ) ) );
 
     return PresentationMorphism( cat, Range( morphism_1 ), XX, Range( morphism_2 ) );