proposition: Lemma semReturnSizeGen A (x : A) (s : nat) : semProdSize (ret x) s <--> [set x].
proof: Proof. rewrite /semProdSize /= /semGenSize. rewrite codom_const; [ reflexivity | apply randomSeed_inhabited ]. Qed.
imports: Coq(String List ZArith Lia) mathcomp.ssreflect.ssreflect mathcomp(ssrfun ssrbool ssrnat eqtype seq) QuickChick(RandomQC RoseTrees Sets Tactics Producer)