Nuprl Lemma : set-axiom-of-choice-implies-xmiddle

Set-AC ⇒ (∀P:ℙ. ((↓P) ∨ (¬P)))


Proof




Definitions occuring in Statement :  set-axiom-of-choice: Set-AC,  prop: ℙ,  all: ∀x:A. B[x],  not: ¬A,  squash: ↓T,  implies: P ⇒ Q,  or: P ∨ Q
Definitions unfolded in proof :  implies: P ⇒ Q,  all: ∀x:A. B[x],  set-axiom-of-choice: Set-AC,  member: t ∈ T,  uall: ∀[x:A]. B[x],  int_seg: {i..j-},  or: P ∨ Q,  prop: ℙ,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  ifthenelse: if b then t else f fi ,  bfalse: ff,  exists: ∃x:A. B[x],  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  assert: ↑b,  false: False,  lelt: i ≤ j < k,  le: A ≤ B,  less_than': less_than'(a;b),  not: ¬A,  less_than: a < b,  squash: ↓T,  true: True,  nequal: a ≠ b ∈ T ,  subtype_rel: A ⊆r B,  decidable: Dec(P),  top: Top,  eq_int: (i =z j),  ext-eq: A ≡ B,  so_lambda: λ2x.t[x],  so_apply: x[s]
Lemmas referenced :  int_seg_wf,  ifthenelse_wf,  eq_int_wf,  or_wf,  equal-wf-T-base,  set-axiom-of-choice_wf,  bool_wf,  eqtt_to_assert,  assert_of_eq_int,  eqff_to_assert,  equal_wf,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot,  neg_assert_of_eq_int,  false_wf,  lelt_wf,  decidable__equal_int_seg,  le_antisymmetry_iff,  add_functionality_wrt_le,  add-associates,  add-swap,  add-commutes,  add-zero,  le-add-cancel,  not_wf,  squash_wf,  subtype_rel_sets
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  sqequalHypSubstitution,  cut,  hypothesis,  dependent_functionElimination,  thin,  introduction,  extract_by_obid,  isectElimination,  natural_numberEquality,  lambdaEquality,  instantiate,  setElimination,  rename,  hypothesisEquality,  universeEquality,  setEquality,  intEquality,  baseClosed,  because_Cache,  independent_functionElimination,  sqequalRule,  unionElimination,  equalityElimination,  equalityTransitivity,  equalitySymmetry,  productElimination,  independent_isectElimination,  dependent_pairFormation,  promote_hyp,  cumulativity,  voidElimination,  dependent_set_memberEquality,  independent_pairFormation,  imageMemberEquality,  inlFormation,  applyEquality,  functionExtensionality,  applyLambdaEquality,  imageElimination,  addEquality,  isect_memberEquality,  voidEquality,  inrFormation

Latex:
Set-AC  {}\mRightarrow{}  (\mforall{}P:\mBbbP{}.  ((\mdownarrow{}P)  \mvee{}  (\mneg{}P)))



Date html generated: 2017_04_14-AM-07_37_44
Last ObjectModification: 2017_02_27-PM-03_10_05

Theory : subtype_1


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