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