Merge pull request #1167 from zickgraf/master

Clean up terminal category and avoid constructing CAP_INTERNAL_TERMINAL_CATEGORY

Author: zickgraf

CAP/PackageInfo.g

@@ -10,7 +10,7 @@ SetPackageInfo( rec(
 
 PackageName := "CAP",
 Subtitle := "Categories, Algorithms, Programming",
-Version := "2022.11-20",
+Version := "2022.11-21",
 Date := Concatenation( "01/", ~.Version{[ 6, 7 ]}, "/", ~.Version{[ 1 .. 4 ]} ),
 License := "GPL-2.0-or-later",
 

CAP/gap/CategoriesCategory.gi

@@ -560,45 +560,25 @@ AddTerminalObject( cat,
 
   function( )
 
-    return CAP_INTERNAL_TERMINAL_CATEGORY_AS_CAT_OBJECT;
-    
-end );
-
-##
-AddUniversalMorphismIntoTerminalObject( cat,
-                               
-  function( category )
-    local new_functor;
-    
-    new_functor := CapFunctor( Concatenation( "The terminal of ", Name( AsCapCategory( category ) ) ), category, CAP_INTERNAL_TERMINAL_CATEGORY_AS_CAT_OBJECT );
-    
-    AddObjectFunction( new_functor,
-                       
-                       function( arg ) return UniqueObject( CAP_INTERNAL_TERMINAL_CATEGORY ); end );
-    
-    AddMorphismFunction( new_functor,
-                         
-                         function( arg ) return UniqueMorphism( CAP_INTERNAL_TERMINAL_CATEGORY ); end );
-    
-    return new_functor;
+    return AsCatObject( TerminalCategoryWithSingleObject( ) );
 
 end );
 
 ##
 AddUniversalMorphismIntoTerminalObjectWithGivenTerminalObject( cat,
 
-  function( category, cat_obj )
+  function( category, terminal_cat )
     local new_functor;
 
-    new_functor := CapFunctor( Concatenation( "The terminal of ", Name( AsCapCategory( category ) ) ), category, CAP_INTERNAL_TERMINAL_CATEGORY_AS_CAT_OBJECT );
+    new_functor := CapFunctor( Concatenation( "The terminal of ", Name( AsCapCategory( category ) ) ), category, terminal_cat );
 
     AddObjectFunction( new_functor,
 
-                       function( arg ) return UniqueObject( CAP_INTERNAL_TERMINAL_CATEGORY ); end );
+                       function( arg ) return UniqueObject( AsCapCategory( terminal_cat ) ); end );
 
     AddMorphismFunction( new_functor,
 
-                         function( arg ) return UniqueMorphism( CAP_INTERNAL_TERMINAL_CATEGORY ); end );
+                         function( arg ) return UniqueMorphism( AsCapCategory( terminal_cat ) ); end );
 
     return new_functor;
 

CAP/gap/DerivedMethods.gi

@@ -3726,17 +3726,18 @@ AddFinalDerivationBundle( # IsomorphismFromCoproductToDirectSum,
 AddFinalDerivationBundle( # RandomObjectByList,
                     [ [ RandomObjectByInteger, 1 ],
                       [ RandomMorphismWithFixedSourceAndRangeByInteger, 1 ],
-                      [ RandomMorphismWithFixedRangeByInteger, 1 ],
                       [ RandomMorphismWithFixedSourceByInteger, 1 ],
+                      [ RandomMorphismWithFixedRangeByInteger, 1 ],
                       [ RandomMorphismByInteger, 1 ],
                     ],
                     [ RandomObjectByList,
                       RandomMorphismWithFixedSourceAndRangeByList,
-                      RandomMorphismWithFixedRangeByList,
                       RandomMorphismWithFixedSourceByList,
+                      RandomMorphismWithFixedRangeByList,
                       RandomMorphismByList ],
 [
   RandomObjectByList,
+  [ [ RandomObjectByInteger, 1 ] ],
   function( cat, L )
 
     if Length( L ) <> 1 or not IsInt( L[1] ) then
@@ -3749,6 +3750,7 @@ AddFinalDerivationBundle( # RandomObjectByList,
 ],
 [
   RandomMorphismWithFixedSourceAndRangeByList,
+  [ [ RandomMorphismWithFixedSourceAndRangeByInteger, 1 ] ],
   function( cat, S, R, L )
 
     if Length( L ) <> 1 or not IsInt( L[1] ) then
@@ -3760,31 +3762,34 @@ AddFinalDerivationBundle( # RandomObjectByList,
   end
 ],
 [
-  RandomMorphismWithFixedRangeByList,
-  function( cat, R, L )
+  RandomMorphismWithFixedSourceByList,
+  [ [ RandomMorphismWithFixedSourceByInteger, 1 ] ],
+  function( cat, S, L )
 
     if Length( L ) <> 1 or not IsInt( L[1] ) then
-        Error( "the list passed to 'RandomMorphismWithFixedRangeByList' in ", Name( cat ), " must consist of only one integer!\n" );
+        Error( "the list passed to 'RandomMorphismWithFixedSourceByList' in ", Name( cat ), " must consist of only one integer!\n" );
     fi;
 
-    return RandomMorphismWithFixedRangeByInteger( cat, R, L[1] );
+    return RandomMorphismWithFixedSourceByInteger( cat, S, L[1] );
 
   end
 ],
 [
-  RandomMorphismWithFixedSourceByList,
-  function( cat, S, L )
+  RandomMorphismWithFixedRangeByList,
+  [ [ RandomMorphismWithFixedRangeByInteger, 1 ] ],
+  function( cat, R, L )
 
     if Length( L ) <> 1 or not IsInt( L[1] ) then
-        Error( "the list passed to 'RandomMorphismWithFixedSourceByList' in ", Name( cat ), " must consist of only one integer!\n" );
+        Error( "the list passed to 'RandomMorphismWithFixedRangeByList' in ", Name( cat ), " must consist of only one integer!\n" );
     fi;
 
-    return RandomMorphismWithFixedSourceByInteger( cat, S, L[1] );
+    return RandomMorphismWithFixedRangeByInteger( cat, R, L[1] );
 
   end
 ],
 [
   RandomMorphismByList,
+  [ [ RandomMorphismByInteger, 1 ] ],
   function( cat, L )
 
     if Length( L ) <> 1 or not IsInt( L[1] ) then
@@ -3794,7 +3799,7 @@ AddFinalDerivationBundle( # RandomObjectByList,
     return RandomMorphismByInteger( cat, L[1] );
 
   end
-]: Description := "Derive all <ByList> random methods from <ByInteger> random methods" );
+] : Description := "Derive all <ByList> random methods from <ByInteger> random methods" );
 
 ## Final methods for homology object
 

CAP/gap/TerminalCategory.gd

@@ -12,29 +12,21 @@
 ########################################
 
 #! @Description
-#!  The ⪆ type of a terminal category.
+#!  The ⪆ type of a terminal category with a single object.
 #! @Arguments T
 DeclareCategory( "IsCapTerminalCategoryWithSingleObject",
         IsCapCategory );
 
 #! @Description
-#!  The ⪆ type of a cell in a terminal category.
-#! @Arguments T
-DeclareCategory( "IsCellInCapTerminalCategoryWithSingleObject",
-        IsCapCategoryCell );
-
-#! @Description
-#!  The ⪆ type of an object in a terminal category.
+#!  The ⪆ type of an object in a terminal category with a single object.
 #! @Arguments T
 DeclareCategory( "IsObjectInCapTerminalCategoryWithSingleObject",
-        IsCellInCapTerminalCategoryWithSingleObject and
         IsCapCategoryObject );
 
 #! @Description
-#!  The ⪆ type of a morphism in a terminal category.
+#!  The ⪆ type of a morphism in a terminal category with a single object.
 #! @Arguments T
 DeclareCategory( "IsMorphismInCapTerminalCategoryWithSingleObject",
-        IsCellInCapTerminalCategoryWithSingleObject and
         IsCapCategoryMorphism );
 
 #! @Description
@@ -43,24 +35,16 @@ DeclareCategory( "IsMorphismInCapTerminalCategoryWithSingleObject",
 DeclareCategory( "IsCapTerminalCategoryWithMultipleObjects",
         IsCapCategory );
 
-#! @Description
-#!  The ⪆ type of a cell in a terminal category with multiple objects.
-#! @Arguments T
-DeclareCategory( "IsCellInCapTerminalCategoryWithMultipleObjects",
-        IsCapCategoryCell );
-
 #! @Description
 #!  The ⪆ type of an object in a terminal category with multiple objects.
 #! @Arguments T
 DeclareCategory( "IsObjectInCapTerminalCategoryWithMultipleObjects",
-        IsCellInCapTerminalCategoryWithMultipleObjects and
         IsCapCategoryObject );
 
 #! @Description
 #!  The ⪆ type of a morphism in a terminal category with multiple objects.
 #! @Arguments T
 DeclareCategory( "IsMorphismInCapTerminalCategoryWithMultipleObjects",
-        IsCellInCapTerminalCategoryWithMultipleObjects and
         IsCapCategoryMorphism );
 
 AddCategoricalProperty( [ "IsTerminalCategory", "IsTerminalCategory" ] );
@@ -71,21 +55,17 @@ AddCategoricalProperty( [ "IsTerminalCategory", "IsTerminalCategory" ] );
 #
 ########################################
 
-DeclareGlobalName( "CAP_INTERNAL_CREATE_TerminalCategory" );
-
 #! @Description
-#!  Construct a terminal category.
-DeclareGlobalFunction( "TerminalCategory" );
-#! @InsertChunk TerminalCategory
+#!  Construct a terminal category with a single object.
+DeclareGlobalFunction( "TerminalCategoryWithSingleObject" );
 
 #! @Description
 #!  Construct a terminal category with multiple objects.
 DeclareGlobalFunction( "TerminalCategoryWithMultipleObjects" );
-#! @InsertChunk TerminalCategoryWithMultipleObjects
 
 #! @Description
 #!  This function takes a record of options suited for CategoryConstructor. 
-#!  It makes common adjustments from TerminalCategory and TerminalCategoryWithMultipleObjects
+#!  It makes common adjustments for TerminalCategoryWithSingleObject and TerminalCategoryWithMultipleObjects
 #!  to the list of operations to install and the categorical properties of the given record,
 #!  before passing it on to CategoryConstructor.
 #! @Arguments options
@@ -99,13 +79,13 @@ DeclareGlobalFunction( "CAP_INTERNAL_CONSTRUCTOR_FOR_TERMINAL_CATEGORY" );
 #########################################
 
 #! @Description
-#!  The unique object in a terminal category.
+#!  The unique object in a terminal category with a single object.
 #! @Returns a ∩ object
 DeclareAttribute( "UniqueObject",
                   IsCapTerminalCategoryWithSingleObject );
 
 #! @Description
-#!  The unique morphism in a terminal category.
+#!  The unique morphism in a terminal category with a single object.
 #! @Returns a ∩ morphism
 DeclareAttribute( "UniqueMorphism",
                   IsCapTerminalCategoryWithSingleObject );
@@ -117,22 +97,8 @@ DeclareAttribute( "UniqueMorphism",
 #########################################
 
 #! @Description
-#!  A functor from a terminal category to another category with a given cell **cell**.
-#! @Arguments cell
-#! @Returns a ∩ morphism
+#!  A functor from `AsCapCategory( TerminalObject( CapCat ) )` mapping the unique object to <A>object</A>.
+#! @Arguments object
+#! @Returns a &CAP; functor
 DeclareAttribute( "FunctorFromTerminalCategory",
-                  IsCapCategoryCell );
-
-#########################################
-#
-#! @Section Variables
-#
-#########################################
-
-#! @Description
-#!  A terminal category.
-DeclareGlobalName( "CAP_INTERNAL_TERMINAL_CATEGORY" );
-
-#! @Description
-#!  A terminal category as an object in CAT.
-DeclareGlobalName( "CAP_INTERNAL_TERMINAL_CATEGORY_AS_CAT_OBJECT" );
+                  IsCapCategoryObject );