Nuprl Lemma : face-zero-and-one
∀[X:j⊢]. ∀[z:{X ⊢ _:𝕀}].  (((z=0) ∧ (z=1)) = 0(𝔽) ∈ {X ⊢ _:𝔽})
Proof
Definitions occuring in Statement : 
face-zero: (i=0)
, 
face-one: (i=1)
, 
face-and: (a ∧ b)
, 
face-0: 0(𝔽)
, 
face-type: 𝔽
, 
interval-type: 𝕀
, 
cubical-term: {X ⊢ _:A}
, 
cubical_set: CubicalSet
, 
uall: ∀[x:A]. B[x]
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
squash: ↓T
, 
true: True
, 
subtype_rel: A ⊆r B
, 
uimplies: b supposing a
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
Lemmas referenced : 
equal_wf, 
cubical-term_wf, 
face-type_wf, 
face-and-com, 
face-zero_wf, 
face-one_wf, 
face-0_wf, 
iff_weakening_equal, 
face-one-and-zero, 
interval-type_wf, 
cubical_set_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
applyEquality, 
thin, 
instantiate, 
lambdaEquality_alt, 
sqequalHypSubstitution, 
imageElimination, 
extract_by_obid, 
isectElimination, 
because_Cache, 
hypothesis, 
hypothesisEquality, 
natural_numberEquality, 
sqequalRule, 
imageMemberEquality, 
baseClosed, 
equalityTransitivity, 
equalitySymmetry, 
independent_isectElimination, 
productElimination, 
independent_functionElimination, 
universeIsType, 
isect_memberEquality_alt, 
axiomEquality, 
isectIsTypeImplies, 
inhabitedIsType
Latex:
\mforall{}[X:j\mvdash{}].  \mforall{}[z:\{X  \mvdash{}  \_:\mBbbI{}\}].    (((z=0)  \mwedge{}  (z=1))  =  0(\mBbbF{}))
Date html generated:
2020_05_20-PM-02_43_24
Last ObjectModification:
2020_04_04-PM-04_57_39
Theory : cubical!type!theory
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