Nuprl Lemma : ps-sigma-unelim-elim

[C:SmallCategory]. ∀[X:ps_context{j:l}(C)]. ∀[A:{X ⊢ _}]. ∀[B:{X.A ⊢ _}].
  (SigmaElim SigmaUnElim 1(X.A.B) ∈ psc_map{[i j]:l}(C; X.A.B; X.A.B))


Proof




Definitions occuring in Statement :  sigma-unelim-pscm: SigmaUnElim sigma-elim-pscm: SigmaElim presheaf-sigma: Σ B psc-adjoin: X.A presheaf-type: {X ⊢ _} pscm-id: 1(X) pscm-comp: F psc_map: A ⟶ B 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 psc-adjoin: X.A all: x:A. B[x] pscm-id: 1(X) sigma-elim-pscm: SigmaElim sigma-unelim-pscm: SigmaUnElim psc-adjoin-set: (v;u) pscm-comp: F compose: g spreadn: spread3 uimplies: supposing a I_set: A(I) functor-ob: ob(F) pi1: fst(t)
Lemmas referenced :  presheaf-type_wf psc-adjoin_wf small-category-cumulativity-2 ps_context_cumulativity2 presheaf-type-cumulativity2 ps_context_wf small-category_wf pscm-comp_wf presheaf-sigma_wf sigma-unelim-pscm_wf sigma-elim-pscm_wf pscm-id_wf I_set_pair_redex_lemma psc_restriction_pair_lemma I_set_wf cat-ob_wf pscm-equal presheaf-type-at_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt introduction cut hypothesis universeIsType thin instantiate extract_by_obid sqequalHypSubstitution isectElimination hypothesisEquality applyEquality sqequalRule isect_memberEquality_alt axiomEquality isectIsTypeImplies inhabitedIsType because_Cache functionExtensionality dependent_functionElimination Error :memTop,  productElimination independent_isectElimination dependent_pairEquality_alt

Latex:
\mforall{}[C:SmallCategory].  \mforall{}[X:ps\_context\{j:l\}(C)].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[B:\{X.A  \mvdash{}  \_\}].
    (SigmaElim  o  SigmaUnElim  =  1(X.A.B))



Date html generated: 2020_05_20-PM-01_32_45
Last ObjectModification: 2020_04_02-PM-06_45_38

Theory : presheaf!models!of!type!theory


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