Nuprl Lemma : singleton-contraction_wf
∀[X:j⊢]. ∀[T:{X ⊢ _}]. ∀[a,b:{X ⊢ _:T}]. ∀[pth:{X ⊢ _:(Path_T a b)}].
  (singleton-contraction(X;pth) ∈ {X ⊢ _:(Path_Σ T (Path_(T)p (a)p q) cubical-pair(a;refl(a)) cubical-pair(b;pth))})
Proof
Definitions occuring in Statement : 
singleton-contraction: singleton-contraction(X;pth)
, 
cubical-refl: refl(a)
, 
path-type: (Path_A a b)
, 
cubical-pair: cubical-pair(u;v)
, 
cubical-sigma: Σ 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
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
singleton-contraction: singleton-contraction(X;pth)
, 
squash: ↓T
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
all: ∀x:A. B[x]
, 
true: True
, 
uimplies: b supposing a
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
, 
path-point: path-point(pth)
, 
cubical-type: {X ⊢ _}
, 
cc-fst: p
, 
csm-ap-type: (AF)s
, 
interval-type: 𝕀
, 
csm-id: 1(X)
, 
csm-ap: (s)x
, 
cc-snd: q
, 
csm-comp: G o F
, 
constant-cubical-type: (X)
, 
compose: f o g
, 
csm-adjoin: (s;u)
, 
pi1: fst(t)
, 
csm-ap-term: (t)s
, 
same-cubical-term: X ⊢ u=v:A
Lemmas referenced : 
cubical-refl_wf, 
cubical-term_wf, 
squash_wf, 
true_wf, 
equal_wf, 
istype-universe, 
cubical-type_wf, 
cubical_set_cumulativity-i-j, 
path-type_wf, 
cubical-type-cumulativity2, 
csm-path-type, 
cube-context-adjoin_wf, 
csm-id-adjoin_wf, 
csm-ap-type_wf, 
cc-fst_wf, 
csm-ap-term_wf, 
cc-snd_wf, 
subtype_rel_self, 
iff_weakening_equal, 
csm_id_adjoin_fst_type_lemma, 
csm_id_adjoin_fst_term_lemma, 
cc_snd_csm_id_adjoin_lemma, 
csm-id_wf, 
csm-ap-id-term, 
subset-cubical-term2, 
sub_cubical_set_self, 
csm-ap-id-type, 
term-to-path-wf, 
cubical-sigma_wf, 
cubical-pair_wf, 
cubical_set_wf, 
path-contraction_wf, 
path-point_wf, 
interval-type_wf, 
csm-cubical-sigma, 
csm-adjoin_wf, 
csm-comp_wf, 
csm-ap-term-snd-adjoin, 
csm-cubical-pair, 
cubical-path-ap-id-adjoin, 
cubical-path-app-1, 
path-contraction-1, 
cubical-path-app_wf, 
interval-1_wf, 
path-type-q-id-adjoin, 
cubical-path-app-0, 
path-contraction-0, 
interval-0_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
applyEquality, 
instantiate, 
lambdaEquality_alt, 
imageElimination, 
because_Cache, 
hypothesis, 
universeIsType, 
equalityTransitivity, 
equalitySymmetry, 
universeEquality, 
sqequalRule, 
dependent_functionElimination, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
independent_isectElimination, 
productElimination, 
independent_functionElimination, 
Error :memTop, 
hyp_replacement, 
axiomEquality, 
isect_memberEquality_alt, 
isectIsTypeImplies, 
inhabitedIsType, 
lambdaFormation_alt, 
equalityIstype, 
setElimination, 
rename
Latex:
\mforall{}[X:j\mvdash{}].  \mforall{}[T:\{X  \mvdash{}  \_\}].  \mforall{}[a,b:\{X  \mvdash{}  \_:T\}].  \mforall{}[pth:\{X  \mvdash{}  \_:(Path\_T  a  b)\}].
    (singleton-contraction(X;pth)  \mmember{}  \{X  \mvdash{}  \_:(Path\_\mSigma{}  T  (Path\_(T)p  (a)p  q)  cubical-pair(a;refl(a))
                                                                                              cubical-pair(b;pth))\})
Date html generated:
2020_05_20-PM-03_29_03
Last ObjectModification:
2020_04_07-PM-05_36_34
Theory : cubical!type!theory
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