canonical insert operation; generalized lemma foldl_apply_inv to foldl_apply
canonical insert operation; generalized lemma foldl_apply_inv to foldl_apply

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