proposition: Lemma eq_ptrP : Equality.axiom eq_ptr.
proof: Proof. by case=>x [y] /=; case: eqP=>[->|*]; constructor=>//; case. Qed.
imports: Coq(ssreflect ssrbool ssrfun Eqdep) mathcomp(ssrnat eqtype seq path) pcm(options axioms finmap) pcm(pcm unionmap)