Nuprl Lemma : presheaf-term-equal2

[C:SmallCategory]. ∀[X:ps_context{j:l}(C)]. ∀[A:{X ⊢ _}]. ∀[u,z:{X ⊢ _:A}].
  z ∈ {X ⊢ _:A} supposing ∀I:cat-ob(C). ∀a:X(I).  ((u a) (z a) ∈ A(a))


Proof




Definitions occuring in Statement :  presheaf-term: {X ⊢ _:A} presheaf-type-at: A(a) presheaf-type: {X ⊢ _} I_set: A(I) ps_context: __⊢ uimplies: supposing a uall: [x:A]. B[x] all: x:A. B[x] apply: a equal: t ∈ T cat-ob: cat-ob(C) small-category: SmallCategory
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a presheaf-term: {X ⊢ _:A} all: x:A. B[x] presheaf-term-at: u(a) subtype_rel: A ⊆B guard: {T}
Lemmas referenced :  I_set_wf cat-ob_wf presheaf-term-at-morph cat-arrow_wf presheaf-type-at_wf psc-restriction_wf presheaf-type-ap-morph_wf small-category-cumulativity-2 ps_context_cumulativity2 presheaf-term_wf presheaf-type_wf ps_context_wf small-category_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt introduction cut dependent_set_memberEquality_alt functionExtensionality_alt universeIsType extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis lambdaFormation_alt sqequalRule applyEquality because_Cache functionIsType equalityIstype instantiate setElimination rename isect_memberEquality_alt axiomEquality isectIsTypeImplies inhabitedIsType dependent_functionElimination

Latex:
\mforall{}[C:SmallCategory].  \mforall{}[X:ps\_context\{j:l\}(C)].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[u,z:\{X  \mvdash{}  \_:A\}].
    u  =  z  supposing  \mforall{}I:cat-ob(C).  \mforall{}a:X(I).    ((u  I  a)  =  (z  I  a))



Date html generated: 2020_05_20-PM-01_26_47
Last ObjectModification: 2020_04_01-PM-01_54_45

Theory : presheaf!models!of!type!theory


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