Section DerivableRules.
Context {L: Language}
{minL: MinimumLanguage L}
{pL: PropositionalLanguage L}
{Gamma: Provable L}
{minAX: MinimumAxiomatization L Gamma}
{ipAX: IntuitionisticPropositionalLogic L Gamma}.

Lemma andp_orp_distr_r: forall x y z: expr,
|-- x && (y || z) <--> (x && y) || (x && z).