GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
##################################################################### ##################################################################### DeclareCategory("IsHapPureCubicalLink",IsObject); DeclareRepresentation( "IsHapPureCubicalLinkRep", IsComponentObjectRep and IsHapPureCubicalComplex, ["binaryArray", "name", "properties"]); HapPureCubicalLinkFamily:=NewFamily( "HapPureCubicalLinkFamily", IsHapPureCubicalLink, IsHapPureCubicalLink); HapPureCubicalLink:=NewType(HapPureCubicalLinkFamily,IsHapPureCubicalLinkRep); InstallMethod( ViewObj, "for HapPureCubicalLink", [IsHapPureCubicalLink], function(T) if EvaluateProperty(T,"knot") then Print(T!.name,"\n"); else Print("Pure cubical link.\n"); fi; end); InstallMethod( PrintObj, "for HapPureCubicalLink", [IsHapPureCubicalLink], function(T) if EvaluateProperty(T,"knot") then Print(T!.name,"\n"); else Print("Pure cubical link.\n"); fi; end); ##################################################################### #####################################################################