Nuprl Lemma : presheaf-sigma-equal

∀[C:SmallCategory]. ∀[X:ps_context{j:l}(C)]. ∀[A:{X ⊢ _}]. ∀[B:{X.A ⊢ _}]. ∀[w,y:{X ⊢ _:Σ A B}].
  (w = y ∈ {X ⊢ _:Σ A B}) supposing ((w.2 = y.2 ∈ {X ⊢ _:(B)[w.1]}) and (w.1 = y.1 ∈ {X ⊢ _:A}))


Proof




Definitions occuring in Statement :  presheaf-snd: p.2,  presheaf-fst: p.1,  presheaf-sigma: Σ A B,  pscm-id-adjoin: [u],  psc-adjoin: X.A,  presheaf-term: {X ⊢ _:A},  pscm-ap-type: (AF)s,  presheaf-type: {X ⊢ _},  ps_context: __⊢,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  equal: s = t ∈ T,  small-category: SmallCategory
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  squash: ↓T,  subtype_rel: A ⊆r B,  true: True,  and: P ∧ Q
Lemmas referenced :  presheaf-pair-eta,  presheaf-pair_wf,  presheaf-term_wf,  pscm-ap-type_wf,  psc-adjoin_wf,  ps_context_cumulativity2,  presheaf-type-cumulativity2,  pscm-id-adjoin_wf,  small-category-cumulativity-2,  presheaf-fst_wf,  presheaf-snd_wf,  subtype_rel-equal,  presheaf-sigma_wf,  presheaf-type_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  introduction,  cut,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  because_Cache,  applyEquality,  lambdaEquality_alt,  imageElimination,  equalityTransitivity,  hypothesis,  equalitySymmetry,  universeIsType,  instantiate,  sqequalRule,  natural_numberEquality,  imageMemberEquality,  baseClosed,  equalityIstype,  independent_isectElimination,  dependent_set_memberEquality_alt,  independent_pairFormation,  productIsType,  inhabitedIsType,  applyLambdaEquality,  setElimination,  rename,  productElimination,  isect_memberEquality_alt,  axiomEquality,  isectIsTypeImplies

Latex:
\mforall{}[C:SmallCategory].  \mforall{}[X:ps\_context\{j:l\}(C)].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[B:\{X.A  \mvdash{}  \_\}].  \mforall{}[w,y:\{X  \mvdash{}  \_:\mSigma{}  A  B\}].
    (w  =  y)  supposing  ((w.2  =  y.2)  and  (w.1  =  y.1))



Date html generated: 2020_05_20-PM-01_33_37
Last ObjectModification: 2020_04_03-AM-01_04_48

Theory : presheaf!models!of!type!theory


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