proposition: Lemma dnf_to_form_qf bcs : qf_form (dnf_to_form bcs).
proof: Proof. by elim: bcs => //= [[clT clF] _ ->] /=; elim: clT => //=; elim: clF. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop prime binomial)