Nuprl Lemma : presheaf-fun-equal2
∀[C:SmallCategory]. ∀[X:ps_context{j:l}(C)]. ∀[A,B:{X ⊢ _}]. ∀[f:{X ⊢ _:(A ⟶ B)}]. ∀[g:I:cat-ob(C)
                                                                                        ⟶ a:X(I)
                                                                                        ⟶ J:cat-ob(C)
                                                                                        ⟶ h:(cat-arrow(C) J I)
                                                                                        ⟶ u:A(h(a))
                                                                                        ⟶ B(h(a))].
  f = g ∈ {X ⊢ _:(A ⟶ B)} 
  supposing ∀[I:cat-ob(C)]. ∀[a:X(I)]. ∀[J:cat-ob(C)]. ∀[h:cat-arrow(C) J I]. ∀[u:A(h(a))].
              ((f(a) J h u) = (g(a) J h u) ∈ B(h(a)))
Proof
Definitions occuring in Statement : 
presheaf-fun: (A ⟶ B), 
presheaf-term-at: u(a), 
presheaf-term: {X ⊢ _:A}, 
presheaf-type-at: A(a), 
presheaf-type: {X ⊢ _}, 
psc-restriction: f(s), 
I_set: A(I), 
ps_context: __⊢, 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
apply: f a, 
function: x:A ⟶ B[x], 
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], 
uimplies: b supposing a, 
member: t ∈ T, 
subtype_rel: A ⊆r B, 
presheaf-term: {X ⊢ _:A}, 
presheaf-term-at: u(a), 
presheaf-fun: (A ⟶ B), 
all: ∀x:A. B[x], 
presheaf-fun-family: presheaf-fun-family(C; X; A; B; I; a), 
squash: ↓T, 
true: True, 
prop: ℙ, 
guard: {T}, 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
rev_implies: P ⇐ Q, 
implies: P ⇒ Q
Lemmas referenced : 
cat-ob_wf, 
I_set_wf, 
cat-arrow_wf, 
presheaf-type-at_wf, 
psc-restriction_wf, 
presheaf-term_wf, 
presheaf-fun_wf, 
presheaf-type_wf, 
ps_context_wf, 
small-category-cumulativity-2, 
small-category_wf, 
presheaf-fun-equal, 
presheaf_type_at_pair_lemma, 
presheaf_type_ap_morph_pair_lemma, 
presheaf-type-ap-morph_wf, 
cat-comp_wf, 
subtype_rel-equal, 
psc-restriction-comp, 
equal_wf, 
squash_wf, 
true_wf, 
istype-universe, 
subtype_rel_self, 
iff_weakening_equal, 
presheaf-term-at-morph, 
presheaf-term-at_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
functionIsType, 
universeIsType, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
because_Cache, 
applyEquality, 
instantiate, 
sqequalRule, 
independent_isectElimination, 
dependent_set_memberEquality_alt, 
functionExtensionality, 
setElimination, 
rename, 
dependent_functionElimination, 
Error :memTop, 
lambdaFormation_alt, 
inhabitedIsType, 
equalityIstype, 
lambdaEquality_alt, 
imageElimination, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
equalitySymmetry, 
equalityTransitivity, 
universeEquality, 
productElimination, 
independent_functionElimination, 
applyLambdaEquality, 
isectIsType
Latex:
\mforall{}[C:SmallCategory].  \mforall{}[X:ps\_context\{j:l\}(C)].  \mforall{}[A,B:\{X  \mvdash{}  \_\}].  \mforall{}[f:\{X  \mvdash{}  \_:(A  {}\mrightarrow{}  B)\}].
\mforall{}[g:I:cat-ob(C)  {}\mrightarrow{}  a:X(I)  {}\mrightarrow{}  J:cat-ob(C)  {}\mrightarrow{}  h:(cat-arrow(C)  J  I)  {}\mrightarrow{}  u:A(h(a))  {}\mrightarrow{}  B(h(a))].
    f  =  g 
    supposing  \mforall{}[I:cat-ob(C)].  \mforall{}[a:X(I)].  \mforall{}[J:cat-ob(C)].  \mforall{}[h:cat-arrow(C)  J  I].  \mforall{}[u:A(h(a))].
                            ((f(a)  J  h  u)  =  (g(a)  J  h  u))
Date html generated:
2020_05_20-PM-01_29_51
Last ObjectModification:
2020_04_02-PM-06_22_58
Theory : presheaf!models!of!type!theory
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