Nuprl Lemma : presheaf-type-ap-morph-id
∀[C:SmallCategory]. ∀[X:ps_context{j:l}(C)]. ∀[A:{X ⊢ _}]. ∀[I:cat-ob(C)]. ∀[f:cat-arrow(C) I I]. ∀[a:X(I)]. ∀[u:A(a)].
  (u a f) = u ∈ A(a) supposing f = (cat-id(C) I) ∈ (cat-arrow(C) I I)
Proof
Definitions occuring in Statement : 
presheaf-type-ap-morph: (u a f)
, 
presheaf-type-at: A(a)
, 
presheaf-type: {X ⊢ _}
, 
I_set: A(I)
, 
ps_context: __⊢
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
apply: f a
, 
equal: s = t ∈ T
, 
cat-id: cat-id(C)
, 
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
, 
uimplies: b supposing a
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
squash: ↓T
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
, 
true: True
, 
presheaf-type: {X ⊢ _}
, 
presheaf-type-ap-morph: (u a f)
, 
all: ∀x:A. B[x]
, 
pi2: snd(t)
Lemmas referenced : 
equal_wf, 
presheaf-type-at_wf, 
presheaf-type-ap-morph_wf, 
subtype_rel-equal, 
psc-restriction_wf, 
small-category-cumulativity-2, 
ps_context_cumulativity2, 
squash_wf, 
true_wf, 
istype-universe, 
I_set_wf, 
psc-restriction-when-id, 
subtype_rel_self, 
iff_weakening_equal, 
cat-id_wf, 
cat-arrow_wf, 
cat-ob_wf, 
presheaf-type_wf, 
ps_context_wf, 
small-category_wf, 
presheaf_type_at_pair_lemma
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
dependent_set_memberEquality_alt, 
hypothesis, 
because_Cache, 
equalityIstype, 
hypothesisEquality, 
equalityTransitivity, 
equalitySymmetry, 
thin, 
hyp_replacement, 
applyLambdaEquality, 
setElimination, 
rename, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
applyEquality, 
instantiate, 
sqequalRule, 
independent_isectElimination, 
lambdaEquality_alt, 
imageElimination, 
universeIsType, 
universeEquality, 
imageMemberEquality, 
baseClosed, 
productElimination, 
independent_functionElimination, 
natural_numberEquality, 
inhabitedIsType, 
isect_memberEquality_alt, 
axiomEquality, 
isectIsTypeImplies, 
dependent_functionElimination, 
Error :memTop
Latex:
\mforall{}[C:SmallCategory].  \mforall{}[X:ps\_context\{j:l\}(C)].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[I:cat-ob(C)].  \mforall{}[f:cat-arrow(C)  I  I].
\mforall{}[a:X(I)].  \mforall{}[u:A(a)].
    (u  a  f)  =  u  supposing  f  =  (cat-id(C)  I)
Date html generated:
2020_05_20-PM-01_26_03
Last ObjectModification:
2020_04_01-PM-00_01_24
Theory : presheaf!models!of!type!theory
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