Nuprl Lemma : cubical-type-ap-morph-comp-eq
∀[X:j⊢]. ∀[A:{X ⊢ _}]. ∀[I,J,K:fset(ℕ)]. ∀[f:J ⟶ I]. ∀[g:K ⟶ J]. ∀[a:X(I)]. ∀[b:X(J)]. ∀[u:A(a)].
  ((u a f) b g) = (u a f ⋅ g) ∈ A(f ⋅ g(a)) supposing b = f(a) ∈ X(J)
Proof
Definitions occuring in Statement : 
cubical-type-ap-morph: (u a f), 
cubical-type-at: A(a), 
cubical-type: {X ⊢ _}, 
cube-set-restriction: f(s), 
I_cube: A(I), 
cubical_set: CubicalSet, 
nh-comp: g ⋅ f, 
names-hom: I ⟶ J, 
fset: fset(T), 
nat: ℕ, 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
uimplies: b supposing a, 
squash: ↓T, 
prop: ℙ, 
subtype_rel: A ⊆r B, 
true: True, 
guard: {T}, 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
rev_implies: P ⇐ Q, 
implies: P ⇒ Q
Lemmas referenced : 
equal_wf, 
squash_wf, 
true_wf, 
istype-universe, 
cubical-type-at_wf, 
cube-set-restriction_wf, 
nh-comp_wf, 
cubical-type-ap-morph-comp-eq-general, 
cubical-type-ap-morph_wf, 
cubical_set_cumulativity-i-j, 
cubical-type-cumulativity2, 
subtype_rel_self, 
iff_weakening_equal, 
istype-cubical-type-at, 
I_cube_wf, 
names-hom_wf, 
fset_wf, 
nat_wf, 
cubical-type_wf, 
cubical_set_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
applyEquality, 
thin, 
lambdaEquality_alt, 
sqequalHypSubstitution, 
imageElimination, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
equalityTransitivity, 
hypothesis, 
equalitySymmetry, 
universeIsType, 
instantiate, 
universeEquality, 
independent_isectElimination, 
sqequalRule, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
because_Cache, 
productElimination, 
independent_functionElimination, 
equalityIstype, 
inhabitedIsType, 
isect_memberEquality_alt, 
axiomEquality, 
isectIsTypeImplies
Latex:
\mforall{}[X:j\mvdash{}].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[I,J,K:fset(\mBbbN{})].  \mforall{}[f:J  {}\mrightarrow{}  I].  \mforall{}[g:K  {}\mrightarrow{}  J].  \mforall{}[a:X(I)].  \mforall{}[b:X(J)].  \mforall{}[u:A(a)].
    ((u  a  f)  b  g)  =  (u  a  f  \mcdot{}  g)  supposing  b  =  f(a)
Date html generated:
2020_05_20-PM-01_48_32
Last ObjectModification:
2020_04_03-PM-08_26_09
Theory : cubical!type!theory
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