Section Canonical.
Context {L: Language}
{minL: MinimumLanguage L}
{pL: PropositionalLanguage L}
{Gamma: Derivable L}
{bSC: BasicSequentCalculus L Gamma}
{minSC: MinimumSequentCalculus L Gamma}
{ipSC: IntuitionisticPropositionalSequentCalculus L Gamma}
{MD: Model}
{kMD: KripkeModel MD}
{M: Kmodel}
{R: Relation (Kworlds M)}
{SM: Semantics L MD}
{kminSM: KripkeMinimumSemantics L MD M SM}
{kpSM: KripkePropositionalSemantics L MD M SM}.
Context (cP: context -> Prop)
(rel: bijection (Kworlds M) (sig cP)).
Hypothesis H_R: forall m n Phi Psi, rel m Phi -> rel n Psi -> (m <= n <-> Included _ (proj1_sig Phi) (proj1_sig Psi)).

Lemma DeMorgan_canonical_branch_join
{GammaP: Provable L}
{AX: NormalAxiomatization L GammaP Gamma}
{SC: NormalSequentCalculus L GammaP Gamma}
{minAX: MinimumAxiomatization L GammaP}
{ipAX: IntuitionisticPropositionalLogic L GammaP}
{dmpAX: DeMorganPropositionalLogic L GammaP}
(AL_DC: at_least derivable_closed cP)
(AL_OW: at_least orp_witnessed cP)
(AL_CONSI: at_least consistent cP)
(LIN_CD: forall x, Lindenbaum_constructable (cannot_derive x) cP):
BranchJoinKripkeIntuitionisticModel (Kworlds M).