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