Nuprl Lemma : ni-selector-property

∀p:ℕ∞ ⟶ 𝔹. (∃x:ℕ∞. p x = ff ⇐⇒ p ni-selector(p) = ff)


Proof




Definitions occuring in Statement :  ni-selector: ni-selector(p),  nat-inf: ℕ∞,  bfalse: ff,  bool: 𝔹,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  iff: P ⇐⇒ Q,  apply: f a,  function: x:A ⟶ B[x],  equal: s = t ∈ T
Definitions unfolded in proof :  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x],  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  bfalse: ff,  prop: ℙ,  so_lambda: λ2x.t[x],  so_apply: x[s],  rev_implies: P ⇐ Q,  exists: ∃x:A. B[x],  nat: ℕ,  false: False,  ge: i ≥ j ,  uimplies: b supposing a,  satisfiable_int_formula: satisfiable_int_formula(fmla),  not: ¬A,  top: Top,  guard: {T},  subtype_rel: A ⊆r B,  int_seg: {i..j-},  lelt: i ≤ j < k,  le: A ≤ B,  less_than': less_than'(a;b),  decidable: Dec(P),  or: P ∨ Q,  uiff: uiff(P;Q),  assert: ↑b,  ifthenelse: if b then t else f fi ,  true: True,  sq_type: SQType(T),  bnot: ¬bb,  less_than: a < b,  nat-inf: ℕ∞,  ni-selector: ni-selector(p),  nat2inf: n∞,  rev_uimplies: rev_uimplies(P;Q),  nat-inf-infinity: ∞
Lemmas referenced :  nat-inf_wf,  ni-selector_wf,  bool_wf,  equal_wf,  exists_wf,  equal-wf-T-base,  nat_properties,  satisfiable-full-omega-tt,  intformand_wf,  intformle_wf,  itermConstant_wf,  itermVar_wf,  intformless_wf,  int_formula_prop_and_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_less_lemma,  int_formula_prop_wf,  ge_wf,  less_than_wf,  assert_witness,  nat2inf_wf,  less_than_transitivity1,  less_than_irreflexivity,  int_seg_wf,  int_seg_properties,  int_seg_subtype_nat,  false_wf,  decidable__le,  subtract_wf,  intformnot_wf,  itermSubtract_wf,  int_formula_prop_not_lemma,  int_term_value_subtract_lemma,  decidable__equal_int,  int_seg_subtype,  intformeq_wf,  int_formula_prop_eq_lemma,  le_wf,  eqtt_to_assert,  eqff_to_assert,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot,  decidable__lt,  lelt_wf,  itermAdd_wf,  int_term_value_add_lemma,  nat_wf,  not_wf,  assert_wf,  not_assert_elim,  btrue_neq_bfalse,  assert_of_lt_int,  lt_int_wf,  all_wf,  iff_imp_equal_bool,  bnot_wf,  b-exists_wf,  assert-b-exists,  iff_wf,  assert_of_bnot,  true_wf,  equal-nat-inf-infinity,  and_wf,  assert_elim
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  independent_pairFormation,  cut,  applyEquality,  functionExtensionality,  hypothesisEquality,  introduction,  extract_by_obid,  hypothesis,  sqequalHypSubstitution,  isectElimination,  thin,  unionElimination,  equalityElimination,  equalityTransitivity,  equalitySymmetry,  dependent_functionElimination,  independent_functionElimination,  sqequalRule,  lambdaEquality,  baseClosed,  dependent_pairFormation,  functionEquality,  setElimination,  rename,  intWeakElimination,  natural_numberEquality,  independent_isectElimination,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  computeAll,  because_Cache,  productElimination,  applyLambdaEquality,  hypothesis_subsumption,  dependent_set_memberEquality,  promote_hyp,  instantiate,  cumulativity,  addEquality,  hyp_replacement,  addLevel,  impliesFunctionality,  impliesLevelFunctionality,  existsFunctionality,  existsLevelFunctionality

Latex:
\mforall{}p:\mBbbN{}\minfty{}  {}\mrightarrow{}  \mBbbB{}.  (\mexists{}x:\mBbbN{}\minfty{}.  p  x  =  ff  \mLeftarrow{}{}\mRightarrow{}  p  ni-selector(p)  =  ff)



Date html generated: 2017_10_01-AM-08_29_29
Last ObjectModification: 2017_07_26-PM-04_24_01

Theory : basic


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