fixed intern_skolem: disallow internal names (why didn't anybody notice?!?);
fixed intern_skolem: disallow internal names (why didn't anybody notice?!?);

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