proposition: Lemma pickleP : pcancel pickle unpickle.
proof: Proof. move => s. case: s => //= p; by rewrite pickleK. Qed.
imports: mathcomp.ssreflect.ssreflect mathcomp(all_ssreflect) CompDecModal.libs(edone bcase fset base) CompDecModal.CTL(CTL_def)