proposition: Lemma iqsort_nil i : iqsort (i, 0) = Ret tt.
proof: Proof. by rewrite /iqsort Fix_eq //; exact: iqsort'_Fix. Qed.
imports: mathcomp(all_ssreflect) monae_lib hierarchy monad_lib fail_lib state_lib array_lib example_quicksort infotheo(ssr_ext)