proposition: Lemma big_valid_seq (xs : seq I) : valid (\big[PCM.join/Unit]_(i <- xs) g i) = all (fun i => valid (g i)) xs && uniq (\big[cat/[::]]_(i <- xs) dom (g i)).
proof: Proof. by rewrite big_valid_dom_seq. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)