Nuprl Lemma : equiv-witness_wf
∀[G:j⊢]. ∀[A,T:{G ⊢ _}]. ∀[f:{G ⊢ _:(T ⟶ A)}]. ∀[iseq:{G ⊢ _:IsEquiv(T;A;f)}].
  (equiv-witness(f;iseq) ∈ {G ⊢ _:Equiv(T;A)})
Proof
Definitions occuring in Statement : 
equiv-witness: equiv-witness(f;cntr)
, 
cubical-equiv: Equiv(T;A)
, 
is-cubical-equiv: IsEquiv(T;A;w)
, 
cubical-fun: (A ⟶ B)
, 
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]
, 
member: t ∈ T
, 
equiv-witness: equiv-witness(f;cntr)
, 
cubical-equiv: Equiv(T;A)
, 
subtype_rel: A ⊆r B
, 
all: ∀x:A. B[x]
, 
squash: ↓T
, 
prop: ℙ
, 
true: True
, 
uimplies: b supposing a
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
Lemmas referenced : 
cubical-term_wf, 
is-cubical-equiv_wf, 
cubical-type-cumulativity2, 
cubical_set_cumulativity-i-j, 
cubical-fun_wf, 
cubical-type_wf, 
cubical_set_wf, 
cubical-pair_wf, 
cube-context-adjoin_wf, 
csm-ap-type_wf, 
cc-fst_wf, 
cc-snd_wf-cubical-fun, 
squash_wf, 
true_wf, 
equal_wf, 
istype-universe, 
csm-is-cubical-equiv, 
csm-id-adjoin_wf, 
subtype_rel_self, 
iff_weakening_equal, 
csm_id_adjoin_fst_type_lemma, 
csm-ap-id-type, 
cc_snd_csm_id_adjoin_lemma, 
csm-ap-id-term
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
sqequalHypSubstitution, 
hypothesis, 
sqequalRule, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
universeIsType, 
thin, 
instantiate, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
applyEquality, 
isect_memberEquality_alt, 
isectIsTypeImplies, 
inhabitedIsType, 
because_Cache, 
dependent_functionElimination, 
lambdaEquality_alt, 
hyp_replacement, 
imageElimination, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
universeEquality, 
independent_isectElimination, 
productElimination, 
independent_functionElimination, 
Error :memTop
Latex:
\mforall{}[G:j\mvdash{}].  \mforall{}[A,T:\{G  \mvdash{}  \_\}].  \mforall{}[f:\{G  \mvdash{}  \_:(T  {}\mrightarrow{}  A)\}].  \mforall{}[iseq:\{G  \mvdash{}  \_:IsEquiv(T;A;f)\}].
    (equiv-witness(f;iseq)  \mmember{}  \{G  \mvdash{}  \_:Equiv(T;A)\})
Date html generated:
2020_05_20-PM-03_27_22
Last ObjectModification:
2020_04_06-PM-06_45_51
Theory : cubical!type!theory
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