Nuprl Lemma : common-limit-squeeze

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:ℕr0≤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: y int-to-real: r(n) real: nat: so_apply: x[s] all: x:A. B[x] exists: x:A. B[x] implies:  Q and: P ∧ Q function: x:A ⟶ B[x] add: m natural_number: $n
Definitions unfolded in proof :  all: x:A. B[x] implies:  Q member: t ∈ T uall: [x:A]. B[x] so_apply: x[s] prop: so_lambda: λ2x.t[x] and: P ∧ Q nat: ge: i ≥  decidable: Dec(P) or: P ∨ Q uimplies: supposing a not: ¬A satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False converges: x[n]↓ as n→∞ iff: ⇐⇒ Q rev_implies:  Q converges-to: lim n→∞.x[n] y cauchy: cauchy(n.x[n]) sq_exists: x:A [B[x]] nat_plus: + rneq: x ≠ y guard: {T} rbetween: x≤y≤z rleq: x ≤ y rnonneg: rnonneg(x) le: A ≤ B subtype_rel: A ⊆B sq_type: SQType(T) uiff: uiff(P;Q) req_int_terms: t1 ≡ t2 rev_uimplies: rev_uimplies(P;Q) rge: x ≥ y cand: c∧ B sq-all-large: large(n).{P[n]}

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: 2020_05_20-AM-11_09_49
Last ObjectModification: 2019_12_14-PM-00_54_16

Theory : reals


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