Nuprl Lemma : bij-contr_wf
∀X:j⊢. ∀A,B:{X ⊢ _}. ∀f:{X ⊢ _:(A ⟶ B)}. ∀g:{X ⊢ _:(B ⟶ A)}. ∀cA:X +⊢ Compositon(A).
∀b:{X.A ⊢ _:(Path_(A)p app((g)p; app((f)p; q)) q)}. ∀c:{X ⊢ _:Contractible(B)}.
  (bij-contr(X; A; f; g; cA; b; c) ∈ {X ⊢ _:Contractible(A)})
Proof
Definitions occuring in Statement : 
bij-contr: bij-contr(X; A; f; g; cA; b; c)
, 
composition-structure: Gamma ⊢ Compositon(A)
, 
contractible-type: Contractible(A)
, 
path-type: (Path_A a b)
, 
cubical-app: app(w; u)
, 
cubical-fun: (A ⟶ B)
, 
cc-snd: q
, 
cc-fst: p
, 
cube-context-adjoin: X.A
, 
csm-ap-term: (t)s
, 
cubical-term: {X ⊢ _:A}
, 
csm-ap-type: (AF)s
, 
cubical-type: {X ⊢ _}
, 
cubical_set: CubicalSet
, 
all: ∀x:A. B[x]
, 
member: t ∈ T
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
subtype_rel: A ⊆r B
, 
uimplies: b supposing a
, 
bij-contr: bij-contr(X; A; f; g; cA; b; c)
, 
squash: ↓T
, 
prop: ℙ
, 
true: True
Lemmas referenced : 
csm-cubical-fun, 
cc-fst_wf, 
cubical-type-cumulativity2, 
cubical-term-eqcd, 
csm-ap-term_wf, 
cube-context-adjoin_wf, 
cubical-fun_wf, 
cubical_set_cumulativity-i-j, 
cubical-app_wf_fun, 
contr-center_wf, 
contr-witness_wf, 
comp_path_wf, 
csm-comp-structure_wf, 
csm-ap-type_wf, 
istype-cubical-term, 
contractible-type_wf, 
path-type_wf, 
cc-snd_wf, 
composition-structure_wf, 
cubical-type_wf, 
cubical_set_wf, 
map-path_wf, 
contr-path_wf, 
csm-contractible-type, 
squash_wf, 
true_wf, 
csm-contr-center, 
csm-ap-cubical-app-fun
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
cut, 
thin, 
instantiate, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
because_Cache, 
hypothesisEquality, 
isectElimination, 
applyEquality, 
hypothesis, 
sqequalRule, 
equalityTransitivity, 
equalitySymmetry, 
independent_isectElimination, 
lambdaEquality_alt, 
hyp_replacement, 
universeIsType, 
imageElimination, 
inhabitedIsType, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
Error :memTop
Latex:
\mforall{}X:j\mvdash{}.  \mforall{}A,B:\{X  \mvdash{}  \_\}.  \mforall{}f:\{X  \mvdash{}  \_:(A  {}\mrightarrow{}  B)\}.  \mforall{}g:\{X  \mvdash{}  \_:(B  {}\mrightarrow{}  A)\}.  \mforall{}cA:X  +\mvdash{}  Compositon(A).
\mforall{}b:\{X.A  \mvdash{}  \_:(Path\_(A)p  app((g)p;  app((f)p;  q))  q)\}.  \mforall{}c:\{X  \mvdash{}  \_:Contractible(B)\}.
    (bij-contr(X;  A;  f;  g;  cA;  b;  c)  \mmember{}  \{X  \mvdash{}  \_:Contractible(A)\})
Date html generated:
2020_05_20-PM-05_24_50
Last ObjectModification:
2020_04_20-PM-02_17_58
Theory : cubical!type!theory
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