fact: Definition step_plain (D : {fset clause * annot}) (A : clause * annot) := [some s in F, [some C in Cs, [some E in As, (A == (s |` C, E)) && step_plain_cases D C s E]]].
imports: mathcomp.ssreflect.ssreflect mathcomp(all_ssreflect) CompDecModal.libs(edone bcase fset base sltype) CompDecModal.CTL(CTL_def gen_def)