new version of triv_of_class machinery without legacy_unconstrain
new version of triv_of_class machinery without legacy_unconstrain

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