Nuprl Lemma : path-type-ext-eq

∀[X:j⊢]. ∀[A:{X ⊢ _}]. ∀[a,b:{X ⊢ _:A}].
  {t:{X ⊢ _:Path(A)}| (t @ 0(𝕀) = a ∈ {X ⊢ _:A}) ∧ (t @ 1(𝕀) = b ∈ {X ⊢ _:A})}  ≡ {X ⊢ _:(Path_A a b)}


Proof




Definitions occuring in Statement :  path-type: (Path_A a b),  cubicalpath-app: pth @ r,  pathtype: Path(A),  interval-1: 1(𝕀),  interval-0: 0(𝕀),  cubical-term: {X ⊢ _:A},  cubical-type: {X ⊢ _},  cubical_set: CubicalSet,  ext-eq: A ≡ B,  uall: ∀[x:A]. B[x],  and: P ∧ Q,  set: {x:A| B[x]} ,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  ext-eq: A ≡ B,  and: P ∧ Q,  subtype_rel: A ⊆r B,  cubical-term: {X ⊢ _:A},  path-type: (Path_A a b),  cubical-subset: cubical-subset,  all: ∀x:A. B[x],  cand: A c∧ B,  pathtype: Path(A),  cubical-fun: (A ⟶ B),  cubical-fun-family: cubical-fun-family(X; A; B; I; a),  uimplies: b supposing a,  squash: ↓T,  true: True,  respects-equality: respects-equality(S;T),  implies: P ⇒ Q,  prop: ℙ,  interval-0: 0(𝕀),  cubicalpath-app: pth @ r,  cubical-term-at: u(a),  cubical-app: app(w; u),  interval-1: 1(𝕀),  guard: {T},  lattice-point: Point(l),  record-select: r.x,  dM: dM(I),  free-DeMorgan-algebra: free-DeMorgan-algebra(T;eq),  mk-DeMorgan-algebra: mk-DeMorgan-algebra(L;n),  record-update: r[x := v],  ifthenelse: if b then t else f fi ,  eq_atom: x =a y,  bfalse: ff,  free-DeMorgan-lattice: free-DeMorgan-lattice(T;eq),  free-dist-lattice: free-dist-lattice(T; eq),  mk-bounded-distributive-lattice: mk-bounded-distributive-lattice,  mk-bounded-lattice: mk-bounded-lattice(T;m;j;z;o),  btrue: tt,  cubical-type-at: A(a),  pi1: fst(t),  interval-type: 𝕀,  constant-cubical-type: (X),  I_cube: A(I),  functor-ob: ob(F),  interval-presheaf: 𝕀,  cubical-path-app: pth @ r
Lemmas referenced :  cubical-term_wf,  pathtype_wf,  cubical-type-cumulativity2,  cubical_set_cumulativity-i-j,  cubicalpath-app_wf,  interval-0_wf,  interval-1_wf,  path-type_wf,  cubical-type_wf,  cubical_set_wf,  cubical_type_at_pair_lemma,  I_cube_wf,  fset_wf,  nat_wf,  cubical_type_ap_morph_pair_lemma,  names-hom_wf,  istype-cubical-type-at,  cube-set-restriction_wf,  cubical-type-ap-morph_wf,  nh-id_wf,  dM0_wf,  cubical-term-at_wf,  subtype-respects-equality,  cubical-type-at_wf,  subtype_rel-equal,  cube-set-restriction-id,  dM1_wf,  squash_wf,  true_wf,  equal_wf,  istype-universe,  subtype_rel_self,  interval-type_wf,  path-type-subtype,  cubical-path-app-0,  cubical-path-app-1
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  introduction,  cut,  independent_pairFormation,  lambdaEquality_alt,  setIsType,  universeIsType,  thin,  instantiate,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  hypothesisEquality,  applyEquality,  hypothesis,  sqequalRule,  productIsType,  equalityIstype,  because_Cache,  productElimination,  independent_pairEquality,  axiomEquality,  inhabitedIsType,  isect_memberEquality_alt,  isectIsTypeImplies,  setElimination,  rename,  dependent_set_memberEquality_alt,  dependent_functionElimination,  Error :memTop,  functionExtensionality,  lambdaFormation_alt,  functionIsType,  independent_isectElimination,  imageElimination,  natural_numberEquality,  imageMemberEquality,  baseClosed,  independent_functionElimination,  equalityTransitivity,  equalitySymmetry,  hyp_replacement,  universeEquality,  applyLambdaEquality

Latex:
\mforall{}[X:j\mvdash{}].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[a,b:\{X  \mvdash{}  \_:A\}].
    \{t:\{X  \mvdash{}  \_:Path(A)\}|  (t  @  0(\mBbbI{})  =  a)  \mwedge{}  (t  @  1(\mBbbI{})  =  b)\}    \mequiv{}  \{X  \mvdash{}  \_:(Path\_A  a  b)\}



Date html generated: 2020_05_20-PM-03_17_17
Last ObjectModification: 2020_04_06-PM-06_36_07

Theory : cubical!type!theory


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