proposition: Lemma mImpPrv_trans s t u : mImpPrv s t -> mImpPrv t u -> mImpPrv s u.
proof: Proof. move => H1 H2. rule axB; eassumption. Qed.
imports: mathcomp(all_ssreflect) CompDecModal.libs(edone base fset induced_sym) Setoid Morphisms Relation_Definitions