GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
#(C) 2009 Graham Ellis ##################################################################### ##################################################################### DeclareCategory("IsHapCommutativeDiagram",IsObject); DeclareRepresentation( "IsHapCommutativeDiagramRep", IsComponentObjectRep, ["objects", "arrows", "properties"]); HapCommutativeDiagramFamily:=NewFamily( "HapCommutativeDiagramFamily", IsHapCommutativeDiagram, IsHapCommutativeDiagram); HapCommutativeDiagram:=NewType(HapCommutativeDiagramFamily,IsHapCommutativeDiagramRep); InstallMethod( ViewObj, "for HapCommutativeDiagram", [IsHapCommutativeDiagram], function(T) Print("Commutative diagram with ",Size(T!.objects)," objects and ",Size(T!.arrows)," arrows.\n" ); end); InstallMethod( PrintObj, "for HapCommutativeDiagram", [IsHapCommutativeDiagram], function(T) Print("Commutative diagram.\n"); end); ##################################################################### #####################################################################