Simplified some proofs and made them work for new hyp_subst_tac.
Simplified some proofs and made them work for new hyp_subst_tac.

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