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: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 :
all: ∀x:A. B[x]
,
implies: P
⇒ Q
,
member: t ∈ T
,
uall: ∀[x:A]. B[x]
,
so_apply: x[s]
,
prop: ℙ
,
so_lambda: λ2x.t[x]
,
and: P ∧ Q
,
nat: ℕ
,
ge: i ≥ j
,
decidable: Dec(P)
,
or: P ∨ Q
,
uimplies: b supposing a
,
not: ¬A
,
satisfiable_int_formula: satisfiable_int_formula(fmla)
,
exists: ∃x:A. B[x]
,
false: False
,
converges: x[n]↓ as n→∞
,
iff: P
⇐⇒ Q
,
rev_implies: P
⇐ Q
,
converges-to: lim n→∞.x[n] = y
,
cauchy: cauchy(n.x[n])
,
sq_exists: ∃x:A [B[x]]
,
nat_plus: ℕ+
,
rneq: x ≠ y
,
guard: {T}
,
rbetween: x≤y≤z
,
rleq: x ≤ y
,
rnonneg: rnonneg(x)
,
le: A ≤ B
,
subtype_rel: A ⊆r B
,
sq_type: SQType(T)
,
uiff: uiff(P;Q)
,
req_int_terms: t1 ≡ t2
,
rev_uimplies: rev_uimplies(P;Q)
,
rge: x ≥ y
,
cand: A 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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