fixed a Kodkod generation exception in Nitpick, reported by a Karlsruhe user
fixed a Kodkod generation exception in Nitpick, reported by a Karlsruhe user

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