Nuprl Lemma : universe-decode-restriction
∀[X:j⊢]. ∀[t:{X ⊢ _:c𝕌}]. ∀[I,J:fset(ℕ)]. ∀[f:I ⟶ J]. ∀[rho:X(J)].
  (decode(t)(f(rho)) = universe-type(t;J;rho)(f(1)) ∈ Type)
Proof
Definitions occuring in Statement : 
universe-decode: decode(t)
, 
universe-type: universe-type(t;I;a)
, 
cubical-universe: c𝕌
, 
cubical-term: {X ⊢ _:A}
, 
cubical-type-at: A(a)
, 
formal-cube: formal-cube(I)
, 
cube-set-restriction: f(s)
, 
I_cube: A(I)
, 
cubical_set: CubicalSet
, 
nh-id: 1
, 
names-hom: I ⟶ J
, 
fset: fset(T)
, 
nat: ℕ
, 
uall: ∀[x:A]. B[x]
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
universe-type: universe-type(t;I;a)
, 
universe-decode: decode(t)
, 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
implies: P 
⇒ Q
, 
pi1: fst(t)
, 
cubical-universe: c𝕌
, 
closed-cubical-universe: cc𝕌
, 
csm-fibrant-type: csm-fibrant-type(G;H;s;FT)
, 
closed-type-to-type: closed-type-to-type(T)
, 
so_lambda: λ2x.t[x]
, 
subtype_rel: A ⊆r B
, 
so_apply: x[s]
, 
pi2: snd(t)
, 
I_cube: A(I)
, 
functor-ob: ob(F)
, 
formal-cube: formal-cube(I)
, 
names-hom: I ⟶ J
, 
squash: ↓T
, 
context-map: <rho>
, 
csm-ap: (s)x
, 
functor-arrow: arrow(F)
, 
cube-set-restriction: f(s)
, 
prop: ℙ
, 
uimplies: b supposing a
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
true: True
Lemmas referenced : 
cubical_type_at_pair_lemma, 
cubical-term-at-morph, 
cubical-universe_wf, 
cubical-universe-at, 
cubical-term-at_wf, 
I_cube_wf, 
names-hom_wf, 
fset_wf, 
nat_wf, 
istype-cubical-universe-term, 
cubical_set_wf, 
cubical_type_ap_morph_pair_lemma, 
pi2_wf, 
cubical-type_wf, 
formal-cube_wf1, 
composition-op_wf, 
cubical-type-cumulativity2, 
pi1_wf_top, 
csm-ap-type_wf, 
context-map_wf, 
csm-composition_wf, 
cubical-type-at_wf, 
nh-id_wf, 
csm-ap-type-at, 
I_cube_pair_redex_lemma, 
cube_set_restriction_pair_lemma, 
equal_wf, 
squash_wf, 
true_wf, 
istype-universe, 
nh-id-left, 
nh-comp_wf, 
subtype_rel_self, 
iff_weakening_equal, 
nh-id-right
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
sqequalRule, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
Error :memTop, 
hypothesis, 
instantiate, 
isectElimination, 
because_Cache, 
hypothesisEquality, 
equalityTransitivity, 
equalitySymmetry, 
inhabitedIsType, 
lambdaFormation_alt, 
productElimination, 
equalityIstype, 
independent_functionElimination, 
universeIsType, 
applyLambdaEquality, 
lambdaEquality_alt, 
applyEquality, 
independent_pairEquality, 
dependent_pairEquality_alt, 
imageElimination, 
universeEquality, 
imageMemberEquality, 
baseClosed, 
independent_isectElimination, 
natural_numberEquality
Latex:
\mforall{}[X:j\mvdash{}].  \mforall{}[t:\{X  \mvdash{}  \_:c\mBbbU{}\}].  \mforall{}[I,J:fset(\mBbbN{})].  \mforall{}[f:I  {}\mrightarrow{}  J].  \mforall{}[rho:X(J)].
    (decode(t)(f(rho))  =  universe-type(t;J;rho)(f(1)))
Date html generated:
2020_05_20-PM-07_11_43
Last ObjectModification:
2020_04_25-PM-09_14_20
Theory : cubical!type!theory
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