Nuprl Lemma : presheaf-type-ap-morph-comp
∀[C:SmallCategory]. ∀[X:ps_context{j:l}(C)]. ∀[A:{X ⊢ _}]. ∀[I,J,K:cat-ob(C)]. ∀[f:cat-arrow(C) J I].
∀[g:cat-arrow(C) K J]. ∀[a:X(I)]. ∀[u:A(a)].
  (((u a f) f(a) g) = (u a cat-comp(C) K J I g f) ∈ A(cat-comp(C) K J I g f(a)))
Proof
Definitions occuring in Statement : 
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-comp: cat-comp(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
, 
presheaf-type: {X ⊢ _}
, 
presheaf-type-ap-morph: (u a f)
, 
presheaf-type-at: A(a)
, 
pi1: fst(t)
, 
pi2: snd(t)
, 
all: ∀x:A. B[x]
, 
and: P ∧ Q
, 
squash: ↓T
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
true: True
, 
uimplies: b supposing a
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
Lemmas referenced : 
presheaf_type_at_pair_lemma, 
equal_wf, 
squash_wf, 
true_wf, 
istype-universe, 
psc-restriction_wf, 
ps_context_cumulativity2, 
small-category-cumulativity-2, 
cat-comp_wf, 
subtype_rel_self, 
iff_weakening_equal, 
presheaf-type-at_wf, 
cat-arrow_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, 
applyEquality, 
lambdaEquality_alt, 
imageElimination, 
isectElimination, 
hypothesisEquality, 
equalityTransitivity, 
equalitySymmetry, 
universeIsType, 
instantiate, 
universeEquality, 
because_Cache, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
independent_isectElimination, 
independent_functionElimination, 
isect_memberEquality_alt, 
axiomEquality, 
isectIsTypeImplies, 
inhabitedIsType
Latex:
\mforall{}[C:SmallCategory].  \mforall{}[X:ps\_context\{j:l\}(C)].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[I,J,K:cat-ob(C)].
\mforall{}[f:cat-arrow(C)  J  I].  \mforall{}[g:cat-arrow(C)  K  J].  \mforall{}[a:X(I)].  \mforall{}[u:A(a)].
    (((u  a  f)  f(a)  g)  =  (u  a  cat-comp(C)  K  J  I  g  f))
Date html generated:
2020_05_20-PM-01_25_57
Last ObjectModification:
2020_04_01-AM-11_51_01
Theory : presheaf!models!of!type!theory
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