proposition: Lemma label_lcon (x : MType) : lcons (label (tagged x)).
proof: Proof. case: x => p x. case: (boolP (leaf x)) => [/label_DF /FD.(fd_sub) |/label_Dl]; by move/FD.(fd_lcons). Qed.
imports: mathcomp.ssreflect.ssreflect mathcomp(all_ssreflect) CompDecModal.libs(edone bcase fset base sltype) CompDecModal.CTL(CTL_def dags)