Nuprl Lemma : ratio-test-ext

∀x:ℕ ⟶ ℝ. ∀N:ℕ.
  ((∀c:{c:ℝ| (r0 ≤ c) ∧ (c < r1)} . ((∀n:{N...}. (|x[n + 1]| ≤ (c * |x[n]|))) ⇒ Σn.x[n]↓))
  ∧ (∀c:{c:ℝ| r1 < c} . ((∀n:{N...}. ((c * |x[n]|) < |x[n + 1]|)) ⇒ Σn.x[n]↑)))


Proof




Definitions occuring in Statement :  series-diverges: Σn.x[n]↑,  series-converges: Σn.x[n]↓,  rleq: x ≤ y,  rless: x < y,  rabs: |x|,  rmul: a * b,  int-to-real: r(n),  real: ℝ,  int_upper: {i...},  nat: ℕ,  so_apply: x[s],  all: ∀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 :  member: t ∈ T,  so_apply: x[s],  rabs: |x|,  subtract: n - m,  ratio-test,  comparison-test-ext,  series-converges-tail2-ext,  series-converges-rmul-ext,  geometric-series-converges-ext,  series-diverges-trivially,  rless_transitivity2,  rless_functionality,  decidable__le,  any: any x,  rleq_functionality_wrt_implies,  rless-iff4,  rless-iff-large-diff,  rleq_functionality,  regular-less-iff,  decidable__and,  decidable__not,  decidable__less_than',  decidable__implies,  decidable__false,  uall: ∀[x:A]. B[x],  so_lambda: so_lambda(x,y,z,w.t[x; y; z; w]),  so_apply: x[s1;s2;s3;s4],  so_lambda: λ2x.t[x],  top: Top,  uimplies: b supposing a
Lemmas referenced :  ratio-test,  lifting-strict-decide,  istype-void,  strict4-decide,  lifting-strict-less,  comparison-test-ext,  series-converges-tail2-ext,  series-converges-rmul-ext,  geometric-series-converges-ext,  series-diverges-trivially,  rless_transitivity2,  rless_functionality,  decidable__le,  rleq_functionality_wrt_implies,  rless-iff4,  rless-iff-large-diff,  rleq_functionality,  regular-less-iff,  decidable__and,  decidable__not,  decidable__less_than',  decidable__implies,  decidable__false
Rules used in proof :  introduction,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  cut,  instantiate,  extract_by_obid,  hypothesis,  sqequalRule,  thin,  sqequalHypSubstitution,  equalityTransitivity,  equalitySymmetry,  isectElimination,  baseClosed,  isect_memberEquality_alt,  voidElimination,  independent_isectElimination

Latex:
\mforall{}x:\mBbbN{}  {}\mrightarrow{}  \mBbbR{}.  \mforall{}N:\mBbbN{}.
    ((\mforall{}c:\{c:\mBbbR{}|  (r0  \mleq{}  c)  \mwedge{}  (c  <  r1)\}  .  ((\mforall{}n:\{N...\}.  (|x[n  +  1]|  \mleq{}  (c  *  |x[n]|)))  {}\mRightarrow{}  \mSigma{}n.x[n]\mdownarrow{}))
    \mwedge{}  (\mforall{}c:\{c:\mBbbR{}|  r1  <  c\}  .  ((\mforall{}n:\{N...\}.  ((c  *  |x[n]|)  <  |x[n  +  1]|))  {}\mRightarrow{}  \mSigma{}n.x[n]\muparrow{})))



Date html generated: 2019_10_29-AM-10_26_40
Last ObjectModification: 2019_04_02-AM-10_05_04

Theory : reals


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