Nuprl Lemma : presheaf-sigma-equal

[C:SmallCategory]. ∀[X:ps_context{j:l}(C)]. ∀[A:{X ⊢ _}]. ∀[B:{X.A ⊢ _}]. ∀[w,y:{X ⊢ _:Σ B}].
  (w y ∈ {X ⊢ _:Σ 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 B pscm-id-adjoin: [u] psc-adjoin: X.A presheaf-term: {X ⊢ _:A} pscm-ap-type: (AF)s presheaf-type: {X ⊢ _} ps_context: __⊢ uimplies: supposing a uall: [x:A]. B[x] equal: t ∈ T small-category: SmallCategory
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a squash: T subtype_rel: A ⊆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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