Nuprl Lemma : csm-contractible-type

∀[X:j⊢]. ∀[A:{X ⊢ _}]. ∀[Z:j⊢]. ∀[s:Z j⟶ X].  ((Contractible(A))s = Z ⊢ Contractible((A)s) ∈ {Z ⊢ _})


Proof




Definitions occuring in Statement :  contractible-type: Contractible(A),  csm-ap-type: (AF)s,  cubical-type: {X ⊢ _},  cube_set_map: A ⟶ B,  cubical_set: CubicalSet,  uall: ∀[x:A]. B[x],  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  subtype_rel: A ⊆r B,  cube_set_map: A ⟶ B,  psc_map: A ⟶ B,  nat-trans: nat-trans(C;D;F;G),  cat-ob: cat-ob(C),  pi1: fst(t),  op-cat: op-cat(C),  spreadn: spread4,  cube-cat: CubeCat,  fset: fset(T),  quotient: x,y:A//B[x; y],  cat-arrow: cat-arrow(C),  pi2: snd(t),  type-cat: TypeCat,  all: ∀x:A. B[x],  names-hom: I ⟶ J,  cat-comp: cat-comp(C),  compose: f o g,  prop: ℙ,  squash: ↓T,  true: True,  and: P ∧ Q,  uimplies: b supposing a,  contractible-type: Contractible(A),  guard: {T},  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  implies: P ⇒ Q,  cubical-type: {X ⊢ _},  cc-snd: q,  csm-ap-type: (AF)s,  cc-fst: p,  csm-comp: G o F,  csm-ap: (s)x,  csm-adjoin: (s;u),  csm-ap-term: (t)s
Lemmas referenced :  cube_set_map_wf,  cubical-type_wf,  cubical_set_wf,  csm-ap-comp-type,  cubical_set_cumulativity-i-j,  cube-context-adjoin_wf,  csm-ap-type_wf,  cubical-type-cumulativity2,  cc-fst_wf,  subtype_rel_self,  equal_wf,  squash_wf,  true_wf,  istype-universe,  csm-comp_wf,  csm-ap-type-fst-adjoin,  subtype_rel-equal,  csm-cubical-sigma,  cubical-pi_wf,  path-type_wf,  csm-ap-term_wf,  cc-snd_wf,  cubical-sigma_wf,  iff_weakening_equal,  csm-cubical-pi,  csm-adjoin_wf,  csm-adjoin-comp,  csm-comp-type,  cubical-term_wf,  csm-path-type,  csm-ap-term-snd-adjoin
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  introduction,  cut,  hypothesis,  universeIsType,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  sqequalRule,  isect_memberEquality_alt,  axiomEquality,  isectIsTypeImplies,  inhabitedIsType,  instantiate,  applyEquality,  because_Cache,  applyLambdaEquality,  equalitySymmetry,  hyp_replacement,  lambdaEquality_alt,  imageElimination,  equalityTransitivity,  universeEquality,  natural_numberEquality,  imageMemberEquality,  baseClosed,  Error :memTop,  dependent_set_memberEquality_alt,  independent_pairFormation,  productIsType,  equalityIstype,  setElimination,  rename,  productElimination,  independent_isectElimination,  dependent_functionElimination,  independent_functionElimination

Latex:
\mforall{}[X:j\mvdash{}].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[Z:j\mvdash{}].  \mforall{}[s:Z  j{}\mrightarrow{}  X].    ((Contractible(A))s  =  Z  \mvdash{}  Contractible((A)s))



Date html generated: 2020_05_20-PM-03_22_52
Last ObjectModification: 2020_04_07-PM-05_05_19

Theory : cubical!type!theory


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