Nuprl Lemma : close-reals-iff
∀[x,y:ℝ]. ∀[k:ℕ+]. uiff(|x - y| ≤ (r1/r(k));∀m:ℕ+. ((|(x m) - y m| * k) ≤ ((4 * k) + (2 * m))))
Proof
Definitions occuring in Statement :
rdiv: (x/y)
,
rleq: x ≤ y
,
rabs: |x|
,
rsub: x - y
,
int-to-real: r(n)
,
real: ℝ
,
absval: |i|
,
nat_plus: ℕ+
,
uiff: uiff(P;Q)
,
uall: ∀[x:A]. B[x]
,
le: A ≤ B
,
all: ∀x:A. B[x]
,
apply: f a
,
multiply: n * m
,
subtract: n - m
,
add: n + m
,
natural_number: $n
Definitions unfolded in proof :
subtype_rel: A ⊆r B
,
real: ℝ
,
rnonneg: rnonneg(x)
,
rleq: x ≤ y
,
prop: ℙ
,
false: False
,
exists: ∃x:A. B[x]
,
satisfiable_int_formula: satisfiable_int_formula(fmla)
,
not: ¬A
,
decidable: Dec(P)
,
implies: P
⇒ Q
,
rev_implies: P
⇐ Q
,
iff: P
⇐⇒ Q
,
or: P ∨ Q
,
guard: {T}
,
rneq: x ≠ y
,
nat_plus: ℕ+
,
le: A ≤ B
,
all: ∀x:A. B[x]
,
uimplies: b supposing a
,
and: P ∧ Q
,
uiff: uiff(P;Q)
,
member: t ∈ T
,
uall: ∀[x:A]. B[x]
,
rge: x ≥ y
,
rev_uimplies: rev_uimplies(P;Q)
,
rdiv: (x/y)
,
req_int_terms: t1 ≡ t2
,
less_than': less_than'(a;b)
,
rational-approx: (x within 1/n)
,
nequal: a ≠ b ∈ T
,
int_nzero: ℤ-o
,
sq_type: SQType(T)
,
so_apply: x[s]
,
so_lambda: λ2x.t[x]
,
true: True
,
squash: ↓T
,
less_than: a < b
,
sq_exists: ∃x:A [B[x]]
,
rless: x < y
,
nat: ℕ
,
sq_stable: SqStable(P)
,
int-rdiv: (a)/k1
,
has-value: (a)↓
,
int-to-real: r(n)
,
rsub: x - y
,
rabs: |x|
,
rminus: -(x)
,
absval: |i|
,
ge: i ≥ j
,
subtract: n - m
Latex:
\mforall{}[x,y:\mBbbR{}]. \mforall{}[k:\mBbbN{}\msupplus{}]. uiff(|x - y| \mleq{} (r1/r(k));\mforall{}m:\mBbbN{}\msupplus{}. ((|(x m) - y m| * k) \mleq{} ((4 * k) + (2 * m))))
Date html generated:
2020_05_20-AM-11_05_00
Last ObjectModification:
2019_12_28-PM-08_14_32
Theory : reals
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