diff --git a/doc/Test.xml b/doc/Test.xml index 279a3b9a..ea415b74 100644 --- a/doc/Test.xml +++ b/doc/Test.xml @@ -509,7 +509,6 @@ IndeterminateDegrees
IndeterminatesOfGradedAlgebraPresentation
IndeterminatesOfPolynomial
-InitialObject
InnerAutomorphismGroupQuandle
InnerAutomorphismGroupQuandleAsPerm
InverseRingHomomorphism
@@ -536,7 +535,6 @@ SourcePolynomialRing
SourceRelations
StarGraph
-TerminalObject
TermsOfPolynomial
UnivariateMonomialsOfMonomial
CoefficientsRing
diff --git a/doc/Undocumented.xml b/doc/Undocumented.xml index 2d2ddff5..46267a7f 100644 --- a/doc/Undocumented.xml +++ b/doc/Undocumented.xml @@ -1766,9 +1766,6 @@ IndexInSL2O    Examples: ../tutorial/chap11.html1 

-InitialObject    Examples: ../www/SideLinks/About/aboutAbelianCategories.html1  -
-
InnerAutomorphismGroupQuandle    Examples:

InnerAutomorphismGroupQuandleAsPerm    Examples:
@@ -1848,8 +1845,6 @@
StarGraphAttr    Examples:

-TerminalObject    Examples:
-
TermsOfPolynomial    Examples:

UnivariateMonomialsOfMonomial    Examples:
diff --git a/doc/newCategories.xml b/doc/newCategories.xml index d326b55a..30ac38c4 100644 --- a/doc/newCategories.xml +++ b/doc/newCategories.xml @@ -17,10 +17,6 @@

Inputs an object X in some category, and returns the arrow from X to the terminal object in the category.

Examples: ../www/SideLinks/About/aboutAbelianCategories.html1  -

Inputs the name of a category and returns true or false depending on whether the category has an initial object.

Examples: ../www/SideLinks/About/aboutAbelianCategories.html1  - -

Inputs the name of a category and returns true or false depending on whether the category has a terminal object.

Examples: -

Inputs an arrow f in some category, and returns its source.

Examples: ../tutorial/chap2.html1 , ../tutorial/chap4.html2 , ../tutorial/chap7.html3 , ../tutorial/chap8.html4 , ../www/SideLinks/About/aboutAbelianCategories.html5 , ../www/SideLinks/About/aboutNonabelian.html6 , ../www/SideLinks/About/aboutCoefficientSequence.html7 , ../www/SideLinks/About/aboutCoveringSpaces.html8 , ../www/SideLinks/About/aboutCoverinSpaces.html9 , ../www/SideLinks/About/aboutFunctorial.html10 , ../www/SideLinks/About/aboutLieCovers.html11 

Inputs an arrow f in some category, and returns its target.

Examples: ../tutorial/chap1.html1 , ../tutorial/chap2.html2 , ../tutorial/chap7.html3 , ../tutorial/chap8.html4 , ../www/SideLinks/About/aboutAbelianCategories.html5 , ../www/SideLinks/About/aboutCoefficientSequence.html6 , ../www/SideLinks/About/aboutCoveringSpaces.html7 , ../www/SideLinks/About/aboutCoverinSpaces.html8  diff --git a/lib/CategoryTheory/categories.gd b/lib/CategoryTheory/categories.gd index 5ac5fafe..40edd7a9 100644 --- a/lib/CategoryTheory/categories.gd +++ b/lib/CategoryTheory/categories.gd @@ -174,9 +174,6 @@ DeclareAttribute( "Mapping" , IsCategoryArrow ); ## DeclareProperty("IsAbelianCategory", IsString); DeclareProperty("IsAdditiveCategory", IsString); -DeclareAttribute("TerminalObject", IsString); -#DeclareProperty("HasTerminalObject", IsString); -DeclareAttribute("InitialObject", IsString); #changed from Propertry DeclareAttribute("Pullbacks", IsString); #changed from Propertry DeclareAttribute("Pushouts", IsString); #changed from Propertry diff --git a/lib/CategoryTheory/categories.gdold b/lib/CategoryTheory/categories.gdold index 5ac5fafe..40edd7a9 100644 --- a/lib/CategoryTheory/categories.gdold +++ b/lib/CategoryTheory/categories.gdold @@ -174,9 +174,6 @@ DeclareAttribute( "Mapping" , IsCategoryArrow ); ## DeclareProperty("IsAbelianCategory", IsString); DeclareProperty("IsAdditiveCategory", IsString); -DeclareAttribute("TerminalObject", IsString); -#DeclareProperty("HasTerminalObject", IsString); -DeclareAttribute("InitialObject", IsString); #changed from Propertry DeclareAttribute("Pullbacks", IsString); #changed from Propertry DeclareAttribute("Pushouts", IsString); #changed from Propertry diff --git a/lib/CategoryTheory/categories.gi b/lib/CategoryTheory/categories.gi index c16b69b2..cbdb686e 100644 --- a/lib/CategoryTheory/categories.gi +++ b/lib/CategoryTheory/categories.gi @@ -12,9 +12,7 @@ ## BindGlobal("Category_Of_Groups", Objectify( NewType(NewFamily("Category_Of_Groups"), - IsString and - HasInitialObject - and HasTerminalObject), [])); + IsString), [])); ############################################################################# @@ -75,8 +73,8 @@ InstallMethod( InitialArrow, if not CategoryName(A)=Category_Of_Groups then TryNextMethod(); fi; - initial:=Group( () ); - INITIAL:=CategoricalEnrichment(initial,CategoryName(A)); + initial:=Group( () ); + INITIAL:=CategoricalEnrichment(initial,CategoryName(A)); phi:=GroupHomomorphismByFunction(initial,Object(A), x->Identity(Object(A))); return CategoryArrow(INITIAL,A,phi,CategoryName(A)); @@ -99,7 +97,8 @@ InstallMethod( TerminalArrow, terminal:=Group( () ); TERMINAL:=CategoricalEnrichment(terminal,CategoryName(A)); - phi:=GroupHomomorphismByFunction(Object(A), terminal, x->Identity(terminal)); + phi:=GroupHomomorphismByFunction(Object(A), terminal, + x->Identity(terminal)); return CategoryArrow(A,TERMINAL,phi,CategoryName(A)); end); diff --git a/lib/CategoryTheory/categories.giold b/lib/CategoryTheory/categories.giold index 331c080a..d724fbb1 100644 --- a/lib/CategoryTheory/categories.giold +++ b/lib/CategoryTheory/categories.giold @@ -12,9 +12,7 @@ ## Category_Of_Groups:="Category_Of_Groups"; HAP_type:= NewType(NewFamily("Category_Of_Groups"), - IsString and - HasInitialObject - and HasTerminalObject); + IsString); ObjectifyWithAttributes(Category_Of_Groups,HAP_type); MakeReadOnlyGlobal("Category_Of_Groups"); diff --git a/www/SideLinks/About/aboutAbelianCategories.html b/www/SideLinks/About/aboutAbelianCategories.html index 3ec6607a..551c3b87 100644 --- a/www/SideLinks/About/aboutAbelianCategories.html +++ b/www/SideLinks/About/aboutAbelianCategories.html @@ -241,12 +241,6 @@

 Our GAP implementation

gap> #The last line is essentially a commutative diagram. The
gap> #line before it is a diagram which does not commute.

-gap> #Suppose that we need to know if PHI belongs to a category
-gap> #in which there is an initial object.
-
-gap> HasInitialObject(CategoryName(PHI));
-true
-
gap> #Suppose we need to know if some power of the endomorphism PHI
gap> #is equal to the identity