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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