Nuprl Lemma : path-contraction_wf
∀[X:j⊢]. ∀[A:{X ⊢ _}]. ∀[a,b:{X ⊢ _:A}]. ∀[pth:{X ⊢ _:(Path_A a b)}].
  (path-contraction(X;pth) ∈ {X.𝕀 ⊢ _:(Path_(A)p (a)p path-point(pth))})
Proof
Definitions occuring in Statement : 
path-contraction: path-contraction(X;pth), 
path-point: path-point(pth), 
path-type: (Path_A a b), 
interval-type: 𝕀, 
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, 
uall: ∀[x:A]. B[x], 
member: t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
path-contraction: path-contraction(X;pth), 
guard: {T}, 
subtype_rel: A ⊆r B, 
cc-snd: q, 
interval-type: 𝕀, 
cc-fst: p, 
csm-ap-type: (AF)s, 
constant-cubical-type: (X), 
squash: ↓T, 
prop: ℙ, 
uimplies: b supposing a, 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
rev_implies: P ⇐ Q, 
implies: P ⇒ Q, 
true: True, 
all: ∀x:A. B[x], 
csm-ap-term: (t)s, 
csm-id: 1(X), 
csm-ap: (s)x, 
interval-0: 0(𝕀), 
interval-1: 1(𝕀), 
path-point: path-point(pth)
Lemmas referenced : 
cubical-path-app_wf, 
cube-context-adjoin_wf, 
interval-type_wf, 
cubical_set_cumulativity-i-j, 
csm-ap-type_wf, 
cc-fst_wf, 
csm-ap-term_wf, 
interval-meet_wf, 
csm-interval-type, 
cc-snd_wf, 
cubical-term_wf, 
path-type_wf, 
cubical-type-cumulativity2, 
cubical-type_wf, 
cubical_set_wf, 
equal_wf, 
squash_wf, 
true_wf, 
istype-universe, 
path-type-p, 
subtype_rel_self, 
iff_weakening_equal, 
cube_set_map_wf, 
term-to-path_wf, 
csm_id_adjoin_fst_term_lemma, 
csm-cubical-path-app, 
cc_snd_csm_id_adjoin_lemma, 
csm-interval-meet, 
interval-meet-0, 
csm-path-type, 
cubical-path-app-0, 
interval-meet-1
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
instantiate, 
hypothesis, 
hypothesisEquality, 
applyEquality, 
sqequalRule, 
because_Cache, 
equalityTransitivity, 
equalitySymmetry, 
Error :memTop, 
axiomEquality, 
universeIsType, 
isect_memberEquality_alt, 
isectIsTypeImplies, 
inhabitedIsType, 
lambdaEquality_alt, 
imageElimination, 
universeEquality, 
imageMemberEquality, 
baseClosed, 
independent_isectElimination, 
productElimination, 
independent_functionElimination, 
natural_numberEquality, 
hyp_replacement, 
dependent_functionElimination, 
applyLambdaEquality, 
lambdaFormation_alt, 
equalityIstype
Latex:
\mforall{}[X:j\mvdash{}].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[a,b:\{X  \mvdash{}  \_:A\}].  \mforall{}[pth:\{X  \mvdash{}  \_:(Path\_A  a  b)\}].
    (path-contraction(X;pth)  \mmember{}  \{X.\mBbbI{}  \mvdash{}  \_:(Path\_(A)p  (a)p  path-point(pth))\})
Date html generated:
2020_05_20-PM-03_28_22
Last ObjectModification:
2020_04_07-PM-05_30_01
Theory : cubical!type!theory
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