adding lemma to List library for executable equation of the (refl) transitive closure
adding lemma to List library for executable equation of the (refl) transitive closure

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