Nuprl Lemma : Kummer-criterion

∀a,x:ℕ ⟶ ℝ.
  ((lim n→∞.a[n] * x[n] = r0
  ⇒ (∃c:{c:ℝ| r0 < c} 
       ∃N:ℕ
        ((∀n:{N...}. ((r0 < a[n]) ∧ (r0 < x[n])))
        ∧ (∀n:{N...}. ((r0 < a[n]) ∧ (c ≤ ((a[n] * x[n]/x[n + 1]) - a[n + 1]))))))
  ⇒ Σn.x[n]↓)
  ∧ ((∃N:ℕ
       ((∀n:{N...}. ((r0 < a[n]) ∧ (r0 < x[n])))
       ∧ (∀n:{N...}. (((a[n] * x[n]/x[n + 1]) - a[n + 1]) ≤ r0))
       ∧ Σn.(r1/a[N + n])↑))
    ⇒ Σn.x[n]↑))


Proof




Definitions occuring in Statement :  series-diverges: Σn.x[n]↑,  series-converges: Σn.x[n]↓,  converges-to: lim n→∞.x[n] = y,  rdiv: (x/y),  rleq: x ≤ y,  rless: x < y,  rsub: x - y,  rmul: a * b,  int-to-real: r(n),  real: ℝ,  int_upper: {i...},  nat: ℕ,  so_apply: x[s],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q,  set: {x:A| B[x]} ,  function: x:A ⟶ B[x],  add: n + m,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  and: P ∧ Q,  cand: A c∧ B,  implies: P ⇒ Q,  exists: ∃x:A. B[x],  member: t ∈ T,  uall: ∀[x:A]. B[x],  prop: ℙ,  nat: ℕ,  so_apply: x[s],  int_upper: {i...},  ge: i ≥ j ,  decidable: Dec(P),  or: P ∨ Q,  uimplies: b supposing a,  not: ¬A,  satisfiable_int_formula: satisfiable_int_formula(fmla),  false: False,  top: Top,  rless: x < y,  sq_exists: ∃x:A [B[x]],  nat_plus: ℕ+,  rneq: x ≠ y,  guard: {T},  so_lambda: λ2x.t[x],  series-converges: Σn.x[n]↓,  series-sum: Σn.x[n] = a,  converges: x[n]↓ as n→∞,  subtype_rel: A ⊆r B,  le: A ≤ B,  less_than': less_than'(a;b),  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  cauchy: cauchy(n.x[n]),  sq_stable: SqStable(P),  squash: ↓T,  rdiv: (x/y),  uiff: uiff(P;Q),  req_int_terms: t1 ≡ t2,  converges-to: lim n→∞.x[n] = y,  rleq: x ≤ y,  rnonneg: rnonneg(x),  rev_uimplies: rev_uimplies(P;Q),  rge: x ≥ y,  subtract: n - m,  true: True,  int_seg: {i..j-},  lelt: i ≤ j < k,  pointwise-rleq: x[k] ≤ y[k] for k ∈ [n,m],  sq_type: SQType(T),  real: ℝ
Lemmas referenced :  real_wf,  rless_wf,  int-to-real_wf,  istype-nat,  istype-int_upper,  int_upper_properties,  nat_properties,  decidable__le,  full-omega-unsat,  intformand_wf,  intformnot_wf,  intformle_wf,  itermConstant_wf,  itermVar_wf,  istype-int,  int_formula_prop_and_lemma,  istype-void,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  istype-le,  nat_plus_properties,  rleq_wf,  rsub_wf,  rdiv_wf,  itermAdd_wf,  int_term_value_add_lemma,  converges-to_wf,  rmul_wf,  series-diverges_wf,  converges-iff-cauchy-ext,  rsum_wf,  int_seg_subtype_nat,  istype-false,  int_seg_wf,  nat_plus_wf,  small-reciprocal-real,  rless-int,  decidable__lt,  intformless_wf,  int_formula_prop_less_lemma,  rmul_preserves_rless,  itermSubtract_wf,  itermMultiply_wf,  rinv_wf2,  sq_stable__rless,  rless_functionality,  req_transitivity,  rmul-rinv3,  req-iff-rsub-is-0,  real_polynomial_null,  real_term_value_sub_lemma,  real_term_value_mul_lemma,  real_term_value_const_lemma,  real_term_value_var_lemma,  int_term_value_mul_lemma,  istype-less_than,  sq_stable__all,  nat_wf,  le_wf,  rabs_wf,  sq_stable__rleq,  le_witness_for_triv,  imax_wf,  sq_stable__less_than,  intformeq_wf,  int_formula_prop_eq_lemma,  imax_ub,  rleq_functionality_wrt_implies,  rleq_weakening_equal,  rleq_weakening,  radd_wf,  r-triangle-inequality2,  rless_functionality_wrt_implies,  rleq_functionality,  rabs-difference-symmetry,  req_weakening,  radd_functionality_wrt_rleq,  radd-rdiv,  rdiv_functionality,  radd-int,  req-int-fractions,  decidable__equal_int,  rless_transitivity2,  not-le-2,  sq_stable__le,  condition-implies-le,  minus-add,  minus-one-mul,  zero-add,  minus-one-mul-top,  add-associates,  add-swap,  add-commutes,  add_functionality_wrt_le,  add-zero,  le-add-cancel,  rabs_functionality,  rsum-difference,  rsum_functionality_wrt_rleq,  subtype_rel_function,  subtype_rel_self,  subtract_wf,  int_seg_properties,  int_term_value_subtract_lemma,  subtract-add-cancel,  rmul_preserves_rleq,  rmul_preserves_rleq2,  rleq_weakening_rless,  rminus_wf,  itermMinus_wf,  radd_functionality,  rmul_functionality,  rmul-rinv,  real_term_value_add_lemma,  real_term_value_minus_lemma,  squash_wf,  true_wf,  iff_weakening_equal,  rsum_nonneg,  rabs-of-nonneg,  rleq_transitivity,  rsum_linearity2,  upper_subtype_nat,  le_transitivity,  add-subtract-cancel,  rsum-telescopes2,  rabs-bounds,  rinv-mul-as-rdiv,  rsum-zero-req,  rleq-int-fractions2,  radd-preserves-rleq,  ge_wf,  subtract-1-ge-0,  subtype_base_sq,  int_subtype_base,  trivial-int-eq1,  comparison-test-for-divergence,  series-diverges-rmul,  rmul-is-positive,  rmul-nonneg-case1,  series-diverges-tail
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  cut,  sqequalHypSubstitution,  productElimination,  thin,  sqequalRule,  productIsType,  setIsType,  universeIsType,  introduction,  extract_by_obid,  hypothesis,  isectElimination,  natural_numberEquality,  hypothesisEquality,  functionIsType,  setElimination,  rename,  applyEquality,  dependent_set_memberEquality_alt,  dependent_functionElimination,  unionElimination,  independent_isectElimination,  approximateComputation,  independent_functionElimination,  dependent_pairFormation_alt,  lambdaEquality_alt,  int_eqEquality,  isect_memberEquality_alt,  voidElimination,  independent_pairFormation,  because_Cache,  addEquality,  inrFormation_alt,  closedConclusion,  inhabitedIsType,  imageMemberEquality,  baseClosed,  imageElimination,  multiplyEquality,  functionEquality,  equalityTransitivity,  equalitySymmetry,  functionIsTypeImplies,  dependent_set_memberFormation_alt,  applyLambdaEquality,  equalityIstype,  inlFormation_alt,  minusEquality,  promote_hyp,  instantiate,  universeEquality,  intWeakElimination,  cumulativity,  intEquality

Latex:
\mforall{}a,x:\mBbbN{}  {}\mrightarrow{}  \mBbbR{}.
    ((lim  n\mrightarrow{}\minfty{}.a[n]  *  x[n]  =  r0
    {}\mRightarrow{}  (\mexists{}c:\{c:\mBbbR{}|  r0  <  c\} 
              \mexists{}N:\mBbbN{}
                ((\mforall{}n:\{N...\}.  ((r0  <  a[n])  \mwedge{}  (r0  <  x[n])))
                \mwedge{}  (\mforall{}n:\{N...\}.  ((r0  <  a[n])  \mwedge{}  (c  \mleq{}  ((a[n]  *  x[n]/x[n  +  1])  -  a[n  +  1]))))))
    {}\mRightarrow{}  \mSigma{}n.x[n]\mdownarrow{})
    \mwedge{}  ((\mexists{}N:\mBbbN{}
              ((\mforall{}n:\{N...\}.  ((r0  <  a[n])  \mwedge{}  (r0  <  x[n])))
              \mwedge{}  (\mforall{}n:\{N...\}.  (((a[n]  *  x[n]/x[n  +  1])  -  a[n  +  1])  \mleq{}  r0))
              \mwedge{}  \mSigma{}n.(r1/a[N  +  n])\muparrow{}))
        {}\mRightarrow{}  \mSigma{}n.x[n]\muparrow{}))



Date html generated: 2019_10_29-AM-10_27_35
Last ObjectModification: 2018_12_13-PM-02_06_23

Theory : reals


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