Nuprl Lemma : nat-star-retract-property

∀s:ℕ ⟶ ℕ. (∃n:ℕ. 0 < s n ⇐⇒ ∃n:ℕ. 0 < nat-star-retract(s) n)


Proof




Definitions occuring in Statement :  nat-star-retract: nat-star-retract(s),  nat: ℕ,  less_than: a < b,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  iff: P ⇐⇒ Q,  apply: f a,  function: x:A ⟶ B[x],  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  exists: ∃x:A. B[x],  member: t ∈ T,  prop: ℙ,  uall: ∀[x:A]. B[x],  so_lambda: λ2x.t[x],  subtype_rel: A ⊆r B,  so_apply: x[s],  rev_implies: P ⇐ Q,  nat-star: ℕ*,  guard: {T},  int_seg: {i..j-},  lelt: i ≤ j < k,  uimplies: b supposing a,  satisfiable_int_formula: satisfiable_int_formula(fmla),  false: False,  not: ¬A,  top: Top,  decidable: Dec(P),  or: P ∨ Q,  le: A ≤ B,  less_than': less_than'(a;b),  nat: ℕ,  ge: i ≥ j ,  nat-star-retract: nat-star-retract(s),  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  ifthenelse: if b then t else f fi ,  bfalse: ff,  sq_type: SQType(T),  bnot: ¬bb,  assert: ↑b,  less_than: a < b,  squash: ↓T
Lemmas referenced :  exists_wf,  nat_wf,  less_than_wf,  nat-star-retract_wf,  nat-star_wf,  int_seg_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,  int_seg_wf,  decidable__equal_int,  subtract_wf,  int_seg_subtype,  false_wf,  decidable__le,  intformnot_wf,  itermSubtract_wf,  intformeq_wf,  int_formula_prop_not_lemma,  int_term_value_subtract_lemma,  int_formula_prop_eq_lemma,  le_wf,  all_wf,  int_seg_subtype_nat,  decidable__lt,  lelt_wf,  set_wf,  primrec-wf2,  nat_properties,  itermAdd_wf,  int_term_value_add_lemma,  decidable__exists_int_seg,  bl-exists_wf,  upto_wf,  l_member_wf,  lt_int_wf,  bool_wf,  eqtt_to_assert,  assert-bl-exists,  l_exists_functionality,  assert_wf,  iff_weakening_uiff,  subtype_rel_set,  assert_of_lt_int,  eqff_to_assert,  equal_wf,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot,  l_exists_wf,  l_exists_iff,  bnot_wf,  not_wf,  bool_cases,  iff_transitivity,  assert_of_bnot
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  independent_pairFormation,  sqequalHypSubstitution,  productElimination,  thin,  cut,  introduction,  extract_by_obid,  isectElimination,  hypothesis,  sqequalRule,  lambdaEquality,  natural_numberEquality,  applyEquality,  functionExtensionality,  hypothesisEquality,  because_Cache,  setElimination,  rename,  functionEquality,  independent_isectElimination,  dependent_pairFormation,  int_eqEquality,  intEquality,  dependent_functionElimination,  isect_memberEquality,  voidElimination,  voidEquality,  computeAll,  unionElimination,  addLevel,  equalityTransitivity,  equalitySymmetry,  applyLambdaEquality,  levelHypothesis,  hypothesis_subsumption,  dependent_set_memberEquality,  addEquality,  independent_functionElimination,  instantiate,  setEquality,  equalityElimination,  promote_hyp,  cumulativity,  imageElimination,  impliesFunctionality

Latex:
\mforall{}s:\mBbbN{}  {}\mrightarrow{}  \mBbbN{}.  (\mexists{}n:\mBbbN{}.  0  <  s  n  \mLeftarrow{}{}\mRightarrow{}  \mexists{}n:\mBbbN{}.  0  <  nat-star-retract(s)  n)



Date html generated: 2017_04_17-AM-09_55_20
Last ObjectModification: 2017_02_27-PM-05_49_45

Theory : continuity


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