proposition: Lemma ptrA x i j : x.+i.+j = x.+(i+j).
proof: Proof. by case: x=>x; rewrite /ptr_offset addnA. Qed.
imports: Coq(ssreflect ssrbool ssrfun Eqdep) mathcomp(ssrnat eqtype seq path) pcm(options axioms finmap) pcm(pcm unionmap)