Nuprl Lemma : presheaf-term-equal2

∀[C:SmallCategory]. ∀[X:ps_context{j:l}(C)]. ∀[A:{X ⊢ _}]. ∀[u,z:{X ⊢ _:A}].
  u = z ∈ {X ⊢ _:A} supposing ∀I:cat-ob(C). ∀a:X(I).  ((u I a) = (z I 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: b supposing a,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  apply: f a,  equal: s = t ∈ T,  cat-ob: cat-ob(C),  small-category: SmallCategory
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  presheaf-term: {X ⊢ _:A},  all: ∀x:A. B[x],  presheaf-term-at: u(a),  subtype_rel: A ⊆r 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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