Nuprl Lemma : cubical-type-restriction-eq
∀[X:j⊢]. ∀[T,A:{X ⊢ _}]. ∀[a:{X ⊢ _:A}]. ∀[g:I:fset(ℕ) ⟶ alpha:X(I) ⟶ T(alpha) ⟶ A(alpha)].
  cubical-type-restriction(X;T;I,alpha,t.(g I alpha t) = a(alpha) ∈ A(alpha)) 
  supposing ∀I,J:fset(ℕ). ∀f:J ⟶ I. ∀alpha:X(I). ∀t:T(alpha).
              ((g J f(alpha) (t alpha f)) = (g I alpha t alpha f) ∈ A(f(alpha)))
Proof
Definitions occuring in Statement : 
cubical-type-restriction: cubical-type-restriction, 
cubical-term-at: u(a)
, 
cubical-term: {X ⊢ _:A}
, 
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
, 
names-hom: I ⟶ J
, 
fset: fset(T)
, 
nat: ℕ
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
cubical-type-restriction: cubical-type-restriction, 
uall: ∀[x:A]. B[x]
, 
uimplies: b supposing a
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
squash: ↓T
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
true: True
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
equal_wf, 
squash_wf, 
true_wf, 
istype-universe, 
cubical-type-at_wf, 
cube-set-restriction_wf, 
cubical-type-ap-morph_wf, 
cubical-type-cumulativity2, 
cubical_set_cumulativity-i-j, 
cubical-term-at-morph, 
subtype_rel_self, 
iff_weakening_equal, 
istype-cubical-type-at, 
cubical-term-at_wf, 
I_cube_wf, 
names-hom_wf, 
fset_wf, 
nat_wf, 
cubical-term_wf, 
cubical-type_wf, 
cubical_set_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
isect_memberFormation_alt, 
lambdaFormation_alt, 
cut, 
applyEquality, 
thin, 
lambdaEquality_alt, 
sqequalHypSubstitution, 
imageElimination, 
introduction, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
equalityTransitivity, 
hypothesis, 
equalitySymmetry, 
universeIsType, 
instantiate, 
universeEquality, 
because_Cache, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
independent_isectElimination, 
productElimination, 
independent_functionElimination, 
equalityIstype, 
functionIsType, 
inhabitedIsType, 
dependent_functionElimination
Latex:
\mforall{}[X:j\mvdash{}].  \mforall{}[T,A:\{X  \mvdash{}  \_\}].  \mforall{}[a:\{X  \mvdash{}  \_:A\}].  \mforall{}[g:I:fset(\mBbbN{})  {}\mrightarrow{}  alpha:X(I)  {}\mrightarrow{}  T(alpha)  {}\mrightarrow{}  A(alpha)].
    cubical-type-restriction(X;T;I,alpha,t.(g  I  alpha  t)  =  a(alpha)) 
    supposing  \mforall{}I,J:fset(\mBbbN{}).  \mforall{}f:J  {}\mrightarrow{}  I.  \mforall{}alpha:X(I).  \mforall{}t:T(alpha).
                            ((g  J  f(alpha)  (t  alpha  f))  =  (g  I  alpha  t  alpha  f))
Date html generated:
2020_05_20-PM-03_13_23
Last ObjectModification:
2020_04_06-PM-05_16_51
Theory : cubical!type!theory
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