Nuprl Lemma : common-limit-squeeze-ext

∀a,b,c:ℕ ⟶ ℝ.
  ((∀n:ℕ. ((a[n] ≤ a[n + 1]) ∧ (a[n + 1] ≤ b[n + 1]) ∧ (b[n + 1] ≤ b[n])))
  ⇒ lim n→∞.c[n] = r0
  ⇒ (∀n:ℕ. r0≤b[n] - a[n]≤c[n])
  ⇒ (∃y:ℝ. (lim n→∞.a[n] = y ∧ lim n→∞.b[n] = y)))


Proof




Definitions occuring in Statement :  converges-to: lim n→∞.x[n] = y,  rbetween: x≤y≤z,  rleq: x ≤ y,  rsub: x - y,  int-to-real: r(n),  real: ℝ,  nat: ℕ,  so_apply: x[s],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q,  function: x:A ⟶ B[x],  add: n + m,  natural_number: $n
Definitions unfolded in proof :  member: t ∈ T,  so_apply: x[s],  so_lambda: λ2x.t[x],  accelerate: accelerate(k;f),  imax: imax(a;b),  ifthenelse: if b then t else f fi ,  le_int: i ≤z j,  bnot: ¬bb,  lt_int: i <z j,  btrue: tt,  it: ⋅,  bfalse: ff,  common-limit-squeeze,  converges-iff-cauchy,  sq-all-large-and,  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],  top: Top,  uimplies: b supposing a
Lemmas referenced :  common-limit-squeeze,  lifting-strict-decide,  istype-void,  strict4-decide,  lifting-strict-less,  converges-iff-cauchy,  sq-all-large-and
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{}a,b,c:\mBbbN{}  {}\mrightarrow{}  \mBbbR{}.
    ((\mforall{}n:\mBbbN{}.  ((a[n]  \mleq{}  a[n  +  1])  \mwedge{}  (a[n  +  1]  \mleq{}  b[n  +  1])  \mwedge{}  (b[n  +  1]  \mleq{}  b[n])))
    {}\mRightarrow{}  lim  n\mrightarrow{}\minfty{}.c[n]  =  r0
    {}\mRightarrow{}  (\mforall{}n:\mBbbN{}.  r0\mleq{}b[n]  -  a[n]\mleq{}c[n])
    {}\mRightarrow{}  (\mexists{}y:\mBbbR{}.  (lim  n\mrightarrow{}\minfty{}.a[n]  =  y  \mwedge{}  lim  n\mrightarrow{}\minfty{}.b[n]  =  y)))



Date html generated: 2019_10_29-AM-10_11_05
Last ObjectModification: 2019_04_01-PM-10_59_20

Theory : reals


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