Nuprl Lemma : contractible-type-at
∀[X,A,I,rho:Top].  (Contractible(A)(rho) ~ u:A(rho) × cubical-pi-family(X.A;(A)p;(Path_((A)p)p (q)p q);I;(rho;u)))
Proof
Definitions occuring in Statement : 
contractible-type: Contractible(A)
, 
path-type: (Path_A a b)
, 
cubical-pi-family: cubical-pi-family(X;A;B;I;a)
, 
cc-snd: q
, 
cc-fst: p
, 
cc-adjoin-cube: (v;u)
, 
cube-context-adjoin: X.A
, 
csm-ap-term: (t)s
, 
csm-ap-type: (AF)s
, 
cubical-type-at: A(a)
, 
uall: ∀[x:A]. B[x]
, 
top: Top
, 
product: x:A × B[x]
, 
sqequal: s ~ t
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
contractible-type: Contractible(A)
, 
cubical-pi: ΠA B
, 
cubical-sigma: Σ A B
, 
all: ∀x:A. B[x]
, 
top: Top
Lemmas referenced : 
cubical_type_at_pair_lemma, 
top_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalRule, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
hypothesis, 
sqequalAxiom, 
isectElimination, 
hypothesisEquality, 
because_Cache
Latex:
\mforall{}[X,A,I,rho:Top].
    (Contractible(A)(rho)  \msim{}  u:A(rho)  \mtimes{}  cubical-pi-family(X.A;(A)p;(Path\_((A)p)p  (q)p  q);I;(rho;u)))
Date html generated:
2018_05_23-AM-09_39_12
Last ObjectModification:
2018_05_20-PM-06_39_41
Theory : cubical!type!theory
Home
Index