proposition: Lemma domeqUnPt k v1 v2 f1 f2 : dom_eq f1 f2 -> dom_eq (f1 \+ pts k v1) (f2 \+ pts k v2).
proof: Proof. by rewrite (joinC f1) (joinC f2); apply: domeqPtUn. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)