Nuprl Lemma : subsequence-converges

∀a:ℝ. ∀x,y:ℕ ⟶ ℝ.
  ((∃N:ℕ. ∀n:ℕ. ∃m:ℕ. ((n ≤ m) ∧ (y[n] = x[m])) supposing N ≤ n) ⇒ lim n→∞.x[n] = a ⇒ lim n→∞.y[n] = a)


Proof




Definitions occuring in Statement :  converges-to: lim n→∞.x[n] = y,  req: x = y,  real: ℝ,  nat: ℕ,  uimplies: b supposing a,  so_apply: x[s],  le: A ≤ B,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q,  function: x:A ⟶ B[x]
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  converges-to: lim n→∞.x[n] = y,  member: t ∈ T,  sq_exists: ∃x:{A| B[x]},  uall: ∀[x:A]. B[x],  so_lambda: λ2x.t[x],  prop: ℙ,  nat: ℕ,  so_apply: x[s],  nat_plus: ℕ+,  uimplies: b supposing a,  rneq: x ≠ y,  guard: {T},  or: P ∨ Q,  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ Q,  ge: i ≥ j ,  exists: ∃x:A. B[x],  decidable: Dec(P),  satisfiable_int_formula: satisfiable_int_formula(fmla),  false: False,  not: ¬A,  top: Top,  sq_stable: SqStable(P),  rleq: x ≤ y,  rnonneg: rnonneg(x),  le: A ≤ B,  subtype_rel: A ⊆r B,  squash: ↓T,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced :  sq_stable__all,  nat_wf,  le_wf,  rleq_wf,  rabs_wf,  rsub_wf,  rdiv_wf,  int-to-real_wf,  rless-int,  nat_properties,  nat_plus_properties,  decidable__lt,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformless_wf,  itermConstant_wf,  itermVar_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_less_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  rless_wf,  sq_stable__rleq,  less_than'_wf,  squash_wf,  nat_plus_wf,  converges-to_wf,  exists_wf,  all_wf,  isect_wf,  req_wf,  real_wf,  imax_wf,  imax_nat,  decidable__le,  intformle_wf,  intformeq_wf,  int_formula_prop_le_lemma,  int_formula_prop_eq_lemma,  equal_wf,  imax_lb,  rleq_functionality,  rabs_functionality,  rsub_functionality,  req_weakening
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  sqequalHypSubstitution,  cut,  hypothesis,  dependent_functionElimination,  thin,  hypothesisEquality,  setElimination,  rename,  introduction,  extract_by_obid,  isectElimination,  sqequalRule,  lambdaEquality,  functionEquality,  because_Cache,  applyEquality,  functionExtensionality,  natural_numberEquality,  independent_isectElimination,  inrFormation,  productElimination,  independent_functionElimination,  unionElimination,  dependent_pairFormation,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  independent_pairFormation,  computeAll,  independent_pairEquality,  minusEquality,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  imageMemberEquality,  baseClosed,  imageElimination,  productEquality,  dependent_set_memberFormation,  dependent_set_memberEquality,  applyLambdaEquality

Latex:
\mforall{}a:\mBbbR{}.  \mforall{}x,y:\mBbbN{}  {}\mrightarrow{}  \mBbbR{}.
    ((\mexists{}N:\mBbbN{}.  \mforall{}n:\mBbbN{}.  \mexists{}m:\mBbbN{}.  ((n  \mleq{}  m)  \mwedge{}  (y[n]  =  x[m]))  supposing  N  \mleq{}  n)
    {}\mRightarrow{}  lim  n\mrightarrow{}\minfty{}.x[n]  =  a
    {}\mRightarrow{}  lim  n\mrightarrow{}\minfty{}.y[n]  =  a)



Date html generated: 2017_10_03-AM-08_54_11
Last ObjectModification: 2017_07_28-AM-07_36_12

Theory : reals


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