Nuprl Lemma : ps-sigma-unelim-elim-type

[C:SmallCategory]. ∀[X:ps_context{j:l}(C)]. ∀[A:{X ⊢ _}]. ∀[B:{X.A ⊢ _}]. ∀[T:{X.Σ B ⊢ _}].
  (((T)SigmaUnElim)SigmaElim T ∈ {X.Σ B ⊢ _})


Proof




Definitions occuring in Statement :  sigma-unelim-pscm: SigmaUnElim sigma-elim-pscm: SigmaElim presheaf-sigma: Σ B psc-adjoin: X.A pscm-ap-type: (AF)s presheaf-type: {X ⊢ _} ps_context: __⊢ uall: [x:A]. B[x] equal: t ∈ T small-category: SmallCategory
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T subtype_rel: A ⊆B prop: squash: T uimplies: supposing a true: True guard: {T} iff: ⇐⇒ Q and: P ∧ Q implies:  Q
Lemmas referenced :  ps-sigma-elim-unelim pscm-ap-type_wf psc-adjoin_wf ps_context_cumulativity2 presheaf-sigma_wf presheaf-type-cumulativity2 presheaf-type_wf small-category-cumulativity-2 ps_context_wf small-category_wf equal_wf squash_wf true_wf istype-universe pscm-ap-comp-type sigma-elim-pscm_wf sigma-unelim-pscm_wf pscm-ap-type-is-id subtype_rel_self iff_weakening_equal
Rules used in proof :  cut introduction extract_by_obid sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt hypothesis sqequalHypSubstitution isectElimination thin hypothesisEquality applyLambdaEquality instantiate applyEquality because_Cache sqequalRule universeIsType hyp_replacement equalitySymmetry lambdaEquality_alt imageElimination equalityTransitivity universeEquality independent_isectElimination natural_numberEquality imageMemberEquality baseClosed productElimination independent_functionElimination

Latex:
\mforall{}[C:SmallCategory].  \mforall{}[X:ps\_context\{j:l\}(C)].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[B:\{X.A  \mvdash{}  \_\}].  \mforall{}[T:\{X.\mSigma{}  A  B  \mvdash{}  \_\}].
    (((T)SigmaUnElim)SigmaElim  =  T)



Date html generated: 2020_05_20-PM-01_32_49
Last ObjectModification: 2020_04_02-PM-07_04_54

Theory : presheaf!models!of!type!theory


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