Nuprl Lemma : presheaf-term-at-morph

∀[C:SmallCategory]. ∀[X:ps_context{j:l}(C)]. ∀[A:{X ⊢ _}]. ∀[u:{X ⊢ _:A}]. ∀[I:cat-ob(C)]. ∀[a:X(I)]. ∀[J:cat-ob(C)].
∀[f:cat-arrow(C) J I].
  ((u(a) a f) = u(f(a)) ∈ A(f(a)))


Proof




Definitions occuring in Statement :  presheaf-term-at: u(a),  presheaf-term: {X ⊢ _:A},  presheaf-type-ap-morph: (u a f),  presheaf-type-at: A(a),  presheaf-type: {X ⊢ _},  psc-restriction: f(s),  I_set: A(I),  ps_context: __⊢,  uall: ∀[x:A]. B[x],  apply: f a,  equal: s = t ∈ T,  cat-arrow: cat-arrow(C),  cat-ob: cat-ob(C),  small-category: SmallCategory
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  presheaf-type: {X ⊢ _},  presheaf-term: {X ⊢ _:A},  all: ∀x:A. B[x],  presheaf-term-at: u(a),  subtype_rel: A ⊆r B
Lemmas referenced :  presheaf_type_at_pair_lemma,  presheaf_type_ap_morph_pair_lemma,  cat-arrow_wf,  I_set_wf,  cat-ob_wf,  presheaf-term_wf,  presheaf-type_wf,  ps_context_wf,  small-category-cumulativity-2,  small-category_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  introduction,  cut,  sqequalHypSubstitution,  setElimination,  thin,  rename,  productElimination,  sqequalRule,  extract_by_obid,  dependent_functionElimination,  Error :memTop,  hypothesis,  hypothesisEquality,  universeIsType,  applyEquality,  isectElimination,  isect_memberEquality_alt,  axiomEquality,  isectIsTypeImplies,  inhabitedIsType,  instantiate

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



Date html generated: 2020_05_20-PM-01_26_41
Last ObjectModification: 2020_04_01-PM-01_51_05

Theory : presheaf!models!of!type!theory


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