Nuprl Lemma : second-countable-choice

∀[X:𝕌']. ∀[R:ℕ ⟶ (n:ℕ ⟶ (ℕn ⟶ ℕ) ⟶ X) ⟶ ℙ'].
  ((∀n:ℕ. ∃A:n:ℕ ⟶ (ℕn ⟶ ℕ) ⟶ X. R[n;A]) ⇒ (∃B:n:ℕ ⟶ (ℕn ⟶ ℕ) ⟶ X. ∀n:ℕ. R[n;B_n]))


Proof




Definitions occuring in Statement :  predicate-shift: A_x,  int_seg: {i..j-},  nat: ℕ,  uall: ∀[x:A]. B[x],  prop: ℙ,  so_apply: x[s1;s2],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q,  function: x:A ⟶ B[x],  natural_number: $n,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  implies: P ⇒ Q,  exists: ∃x:A. B[x],  member: t ∈ T,  prop: ℙ,  so_lambda: λ2x.t[x],  nat: ℕ,  so_apply: x[s1;s2],  so_apply: x[s],  all: ∀x:A. B[x],  pi1: fst(t),  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  ifthenelse: if b then t else f fi ,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  le: A ≤ B,  less_than': less_than'(a;b),  false: False,  not: ¬A,  int_seg: {i..j-},  ge: i ≥ j ,  lelt: i ≤ j < k,  satisfiable_int_formula: satisfiable_int_formula(fmla),  top: Top,  bfalse: ff,  or: P ∨ Q,  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  assert: ↑b,  int_upper: {i...},  decidable: Dec(P),  subtract: n - m,  predicate-shift: A_x,  seq-single: seq-single(t),  seq-append: seq-append(n;m;s1;s2),  subtype_rel: A ⊆r B,  less_than: a < b,  true: True,  squash: ↓T,  nequal: a ≠ b ∈ T 
Lemmas referenced :  all_wf,  nat_wf,  exists_wf,  int_seg_wf,  equal_wf,  eq_int_wf,  bool_wf,  eqtt_to_assert,  assert_of_eq_int,  false_wf,  le_wf,  int_seg_properties,  nat_properties,  satisfiable-full-omega-tt,  intformand_wf,  intformless_wf,  itermVar_wf,  itermConstant_wf,  intformle_wf,  int_formula_prop_and_lemma,  int_formula_prop_less_lemma,  int_term_value_var_lemma,  int_term_value_constant_lemma,  int_formula_prop_le_lemma,  int_formula_prop_wf,  eqff_to_assert,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot,  neg_assert_of_eq_int,  int_upper_subtype_nat,  nequal-le-implies,  zero-add,  int_upper_properties,  decidable__lt,  intformnot_wf,  int_formula_prop_not_lemma,  lelt_wf,  subtract_wf,  decidable__le,  itermSubtract_wf,  int_term_value_subtract_lemma,  add-member-int_seg2,  intformeq_wf,  itermAdd_wf,  int_formula_prop_eq_lemma,  int_term_value_add_lemma,  add-associates,  add-swap,  add-commutes,  lt_int_wf,  assert_of_lt_int,  less_than_wf,  add-subtract-cancel,  decidable__equal_int,  predicate-shift_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  cut,  hypothesis,  promote_hyp,  thin,  sqequalHypSubstitution,  productElimination,  instantiate,  introduction,  extract_by_obid,  isectElimination,  cumulativity,  sqequalRule,  lambdaEquality,  functionEquality,  natural_numberEquality,  setElimination,  rename,  hypothesisEquality,  applyEquality,  functionExtensionality,  because_Cache,  universeEquality,  dependent_pairFormation,  equalityTransitivity,  equalitySymmetry,  dependent_functionElimination,  independent_functionElimination,  unionElimination,  equalityElimination,  independent_isectElimination,  dependent_set_memberEquality,  independent_pairFormation,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  computeAll,  hypothesis_subsumption,  hyp_replacement,  addEquality,  minusEquality,  lessCases,  sqequalAxiom,  imageMemberEquality,  baseClosed,  imageElimination,  applyLambdaEquality

Latex:
\mforall{}[X:\mBbbU{}'].  \mforall{}[R:\mBbbN{}  {}\mrightarrow{}  (n:\mBbbN{}  {}\mrightarrow{}  (\mBbbN{}n  {}\mrightarrow{}  \mBbbN{})  {}\mrightarrow{}  X)  {}\mrightarrow{}  \mBbbP{}'].
    ((\mforall{}n:\mBbbN{}.  \mexists{}A:n:\mBbbN{}  {}\mrightarrow{}  (\mBbbN{}n  {}\mrightarrow{}  \mBbbN{})  {}\mrightarrow{}  X.  R[n;A])  {}\mRightarrow{}  (\mexists{}B:n:\mBbbN{}  {}\mrightarrow{}  (\mBbbN{}n  {}\mrightarrow{}  \mBbbN{})  {}\mrightarrow{}  X.  \mforall{}n:\mBbbN{}.  R[n;B\_n]))



Date html generated: 2017_04_17-AM-09_36_09
Last ObjectModification: 2017_02_27-PM-05_34_25

Theory : fan-theorem


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