Nuprl Lemma : case-endpoints_wf
∀[G:j⊢]. ∀[A:{G ⊢ _}]. ∀[a,b:{G ⊢ _:A}]. ∀[r:{G ⊢ _:𝕀}].  ([r=0 ⊢→ a; r=1 ⊢→ b] ∈ {G, ((r=0) ∨ (r=1)) ⊢ _:A})
Proof
Definitions occuring in Statement : 
case-endpoints: [r=0 ⊢→ a; r=1 ⊢→ b]
, 
context-subset: Gamma, phi
, 
face-zero: (i=0)
, 
face-one: (i=1)
, 
face-or: (a ∨ b)
, 
interval-type: 𝕀
, 
cubical-term: {X ⊢ _:A}
, 
cubical-type: {X ⊢ _}
, 
cubical_set: CubicalSet
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
case-endpoints: [r=0 ⊢→ a; r=1 ⊢→ b]
, 
member: t ∈ T
, 
subtype_rel: A ⊆r B
, 
uimplies: b supposing a
, 
same-cubical-term: X ⊢ u=v:A
, 
squash: ↓T
, 
prop: ℙ
, 
guard: {T}
, 
true: True
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
Lemmas referenced : 
case-term_wf, 
face-zero_wf, 
face-one_wf, 
thin-context-subset, 
face-or_wf, 
context-subset-term-subtype, 
empty-context-subset-lemma3, 
subtype_rel-equal, 
cubical-term_wf, 
context-subset_wf, 
equal_wf, 
squash_wf, 
true_wf, 
istype-universe, 
cubical-type-cumulativity2, 
cubical_set_cumulativity-i-j, 
face-0_wf, 
face-type_wf, 
face-zero-and-one, 
face-and_wf, 
subtype_rel_self, 
iff_weakening_equal, 
interval-type_wf, 
cubical-type_wf, 
cubical_set_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
because_Cache, 
applyEquality, 
sqequalRule, 
independent_isectElimination, 
Error :memTop, 
instantiate, 
lambdaEquality_alt, 
imageElimination, 
equalityTransitivity, 
equalitySymmetry, 
universeIsType, 
universeEquality, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
productElimination, 
independent_functionElimination
Latex:
\mforall{}[G:j\mvdash{}].  \mforall{}[A:\{G  \mvdash{}  \_\}].  \mforall{}[a,b:\{G  \mvdash{}  \_:A\}].  \mforall{}[r:\{G  \mvdash{}  \_:\mBbbI{}\}].
    ([r=0  \mvdash{}\mrightarrow{}  a;  r=1  \mvdash{}\mrightarrow{}  b]  \mmember{}  \{G,  ((r=0)  \mvee{}  (r=1))  \mvdash{}  \_:A\})
Date html generated:
2020_05_20-PM-04_15_17
Last ObjectModification:
2020_04_10-AM-04_45_16
Theory : cubical!type!theory
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