proposition: Lemma domPtUnXO A (v : A) x i (f : partition (x :-> v) i) : valid (untag f) -> x \in dom (untag f).
proof: Proof. by rewrite partitionE; apply: domPtUnX. Qed.
imports: Coq(ssreflect ssrbool ssrfun Eqdep) mathcomp(ssrnat eqtype seq path) pcm(options axioms finmap) pcm(pcm unionmap)