Nuprl Lemma : discrete-fun-at

∀[A,B:Type]. ∀[f:{() ⊢ _:(discr(A) ⟶ discr(B))}]. ∀[I:fset(ℕ)]. ∀[a:()(I)].
  ((f I a) = (λJ,h,u. (f {} ⋅ {} 1 u)) ∈ (discr(A) ⟶ discr(B))(a))


Proof




Definitions occuring in Statement :  discrete-cubical-type: discr(T),  cubical-fun: (A ⟶ B),  cubical-term: {X ⊢ _:A},  cubical-type-at: A(a),  trivial-cube-set: (),  I_cube: A(I),  nh-id: 1,  empty-fset: {},  fset: fset(T),  nat: ℕ,  it: ⋅,  uall: ∀[x:A]. B[x],  apply: f a,  lambda: λx.A[x],  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  discrete-cubical-type: discr(T),  cubical-fun: (A ⟶ B),  cubical-fun-family: cubical-fun-family(X; A; B; I; a),  all: ∀x:A. B[x],  top: Top,  cubical-term: {X ⊢ _:A},  cubical-type-at: A(a),  pi1: fst(t),  so_lambda: λ2x.t[x],  so_apply: x[s],  prop: ℙ,  trivial-cube-set: (),  cubical-type-ap-morph: (u a f),  pi2: snd(t),  subtype_rel: A ⊆r B,  I_cube: A(I),  functor-ob: ob(F),  unit: Unit,  squash: ↓T,  true: True,  uimplies: b supposing a,  guard: {T},  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ Q,  implies: P ⇒ Q,  names-hom: I ⟶ J,  names: names(I),  false: False,  nh-id: 1,  nh-comp: g ⋅ f,  dma-lift-compose: dma-lift-compose(I;J;eqi;eqj;f;g),  compose: f o g,  dM: dM(I),  dM-lift: dM-lift(I;J;f)
Lemmas referenced :  I_cube_wf,  fset_wf,  nat_wf,  cubical-term_wf,  trivial-cube-set_wf,  cubical-fun_wf,  discrete-cubical-type_wf,  cubical_type_at_pair_lemma,  cubical_type_ap_morph_pair_lemma,  names-hom_wf,  all_wf,  equal_wf,  nh-comp_wf,  I_cube_pair_redex_lemma,  cube_set_restriction_pair_lemma,  subtype_rel_self,  equal-wf-base,  nh-id_wf,  squash_wf,  true_wf,  nh-id-left,  iff_weakening_equal,  empty-fset_wf,  dM0_wf,  names_wf,  it_wf,  member-empty-fset,  dM-lift-0-sq,  set_wf,  nh-id-right
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  because_Cache,  hypothesisEquality,  hypothesis,  cumulativity,  universeEquality,  promote_hyp,  sqequalRule,  dependent_functionElimination,  isect_memberEquality,  voidElimination,  voidEquality,  setElimination,  rename,  dependent_set_memberEquality,  lambdaFormation,  lambdaEquality,  applyEquality,  functionExtensionality,  intEquality,  baseClosed,  applyLambdaEquality,  hyp_replacement,  equalitySymmetry,  imageElimination,  equalityTransitivity,  natural_numberEquality,  imageMemberEquality,  setEquality,  independent_isectElimination,  productElimination,  independent_functionElimination,  functionEquality

Latex:
\mforall{}[A,B:Type].  \mforall{}[f:\{()  \mvdash{}  \_:(discr(A)  {}\mrightarrow{}  discr(B))\}].  \mforall{}[I:fset(\mBbbN{})].  \mforall{}[a:()(I)].
    ((f  I  a)  =  (\mlambda{}J,h,u.  (f  \{\}  \mcdot{}  \{\}  1  u)))



Date html generated: 2017_10_05-AM-02_12_05
Last ObjectModification: 2017_03_02-PM-11_21_53

Theory : cubical!type!theory


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