tweaked Inductive.prove_eqs to allow degenerate definition like "inductive TRUE where TRUE";
tweaked Inductive.prove_eqs to allow degenerate definition like "inductive TRUE where TRUE";

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