Nuprl Lemma : cubical-universe-at-cumulativity
∀[I:fset(ℕ)]. ∀[a:Top].  (c𝕌(a) ⊆r c𝕌'(a))
Proof
Definitions occuring in Statement : 
cubical-universe: c𝕌
, 
cubical-type-at: A(a)
, 
fset: fset(T)
, 
nat: ℕ
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
top: Top
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
subtype_rel: A ⊆r B
, 
cubical-type: {X ⊢ _}
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
uimplies: b supposing a
, 
all: ∀x:A. B[x]
, 
and: P ∧ Q
Lemmas referenced : 
istype-top, 
fset_wf, 
nat_wf, 
composition-op_wf, 
formal-cube_wf1, 
cubical-type-cumulativity2, 
cubical-type_wf, 
cubical-universe-at, 
subtype_rel_dep_function, 
I_cube_wf, 
subtype_rel_universe1, 
names-hom_wf, 
cube-set-restriction_wf, 
nh-id_wf, 
subtype_rel-equal, 
cube-set-restriction-id, 
nh-comp_wf, 
cube-set-restriction-comp
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
sqequalRule, 
axiomEquality, 
hypothesis, 
extract_by_obid, 
sqequalHypSubstitution, 
isect_memberEquality_alt, 
isectElimination, 
thin, 
hypothesisEquality, 
isectIsTypeImplies, 
inhabitedIsType, 
universeIsType, 
Error :memTop, 
lambdaEquality_alt, 
productElimination, 
dependent_pairEquality_alt, 
instantiate, 
applyEquality, 
productIsType, 
setElimination, 
rename, 
dependent_set_memberEquality_alt, 
functionExtensionality, 
cumulativity, 
universeEquality, 
because_Cache, 
independent_isectElimination, 
lambdaFormation_alt, 
functionIsType, 
equalityIstype, 
dependent_functionElimination
Latex:
\mforall{}[I:fset(\mBbbN{})].  \mforall{}[a:Top].    (c\mBbbU{}(a)  \msubseteq{}r  c\mBbbU{}'(a))
Date html generated:
2020_05_20-PM-07_09_14
Last ObjectModification:
2020_04_25-PM-01_33_56
Theory : cubical!type!theory
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