Nuprl Lemma : cubical-sigma-intro

∀G:j⊢. ∀A:{G ⊢ _}. ∀B:{G.A ⊢ _}.  ((∃a:{G ⊢ _:A}. {G ⊢ _:(B)[a]}) ⇒ {G ⊢ _:Σ A B})


Proof




Definitions occuring in Statement :  cubical-sigma: Σ A B,  csm-id-adjoin: [u],  cube-context-adjoin: X.A,  cubical-term: {X ⊢ _:A},  csm-ap-type: (AF)s,  cubical-type: {X ⊢ _},  cubical_set: CubicalSet,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q
Definitions unfolded in proof :  all: ∀x:A. B[x],  member: t ∈ T,  cubical_set: CubicalSet,  uall: ∀[x:A]. B[x],  cube-context-adjoin: X.A,  psc-adjoin: X.A,  I_cube: A(I),  I_set: A(I),  cubical-type-at: A(a),  presheaf-type-at: A(a),  cube-set-restriction: f(s),  psc-restriction: f(s),  cubical-type-ap-morph: (u a f),  presheaf-type-ap-morph: (u a f),  csm-ap-type: (AF)s,  pscm-ap-type: (AF)s,  csm-ap: (s)x,  pscm-ap: (s)x,  csm-id-adjoin: [u],  pscm-id-adjoin: [u],  csm-adjoin: (s;u),  pscm-adjoin: (s;u),  csm-id: 1(X),  pscm-id: 1(X),  cubical-sigma: Σ A B,  presheaf-sigma: Σ A B,  cc-adjoin-cube: (v;u),  psc-adjoin-set: (v;u)
Lemmas referenced :  presheaf-sigma-intro,  cube-cat_wf,  cubical-type-sq-presheaf-type,  cubical-term-sq-presheaf-term
Rules used in proof :  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  dependent_functionElimination,  thin,  hypothesis,  sqequalRule,  isectElimination,  Error :memTop

Latex:
\mforall{}G:j\mvdash{}.  \mforall{}A:\{G  \mvdash{}  \_\}.  \mforall{}B:\{G.A  \mvdash{}  \_\}.    ((\mexists{}a:\{G  \mvdash{}  \_:A\}.  \{G  \mvdash{}  \_:(B)[a]\})  {}\mRightarrow{}  \{G  \mvdash{}  \_:\mSigma{}  A  B\})



Date html generated: 2020_05_20-PM-02_34_41
Last ObjectModification: 2020_04_03-PM-08_45_05

Theory : cubical!type!theory


Home Index