Now uses more carefully designed simpsets to prevent proofs from failing for some strange datatypes with nested recursion.
Now uses more carefully designed simpsets to prevent proofs from
failing for some strange datatypes with nested recursion.

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