fact: Definition AU_M s t (x : MD) := cAU MRel (fun z => label (tagged z) |> s^+) (fun z => label (tagged z) |> t^+) x.
imports: mathcomp.ssreflect.ssreflect mathcomp(all_ssreflect) CompDecModal.libs(edone bcase fset base sltype) CompDecModal.CTL(CTL_def dags)