eliminated opaque signature matching -- tends to cause problems with toplevel pp for abstract types;
eliminated opaque signature matching -- tends to cause problems with toplevel pp for abstract types;

MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle