tuned Type.unify; do *not* declare TVar names as used;
tuned Type.unify;
do *not* declare TVar names as used;

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