Nuprl Lemma : Kummer-criterion
∀a,x:ℕ ⟶ ℝ.
  ((lim n→∞.a[n] * x[n] = r0
  
⇒ (∃c:{c:ℝ| r0 < c} 
       ∃N:ℕ
        ((∀n:{N...}. ((r0 < a[n]) ∧ (r0 < x[n])))
        ∧ (∀n:{N...}. ((r0 < a[n]) ∧ (c ≤ ((a[n] * x[n]/x[n + 1]) - a[n + 1]))))))
  
⇒ Σn.x[n]↓)
  ∧ ((∃N:ℕ
       ((∀n:{N...}. ((r0 < a[n]) ∧ (r0 < x[n])))
       ∧ (∀n:{N...}. (((a[n] * x[n]/x[n + 1]) - a[n + 1]) ≤ r0))
       ∧ Σn.(r1/a[N + n])↑))
    
⇒ Σn.x[n]↑))
Proof
Definitions occuring in Statement : 
series-diverges: Σn.x[n]↑
, 
series-converges: Σn.x[n]↓
, 
converges-to: lim n→∞.x[n] = y
, 
rdiv: (x/y)
, 
rleq: x ≤ y
, 
rless: x < y
, 
rsub: x - y
, 
rmul: a * b
, 
int-to-real: r(n)
, 
real: ℝ
, 
int_upper: {i...}
, 
nat: ℕ
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
exists: ∃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 : 
all: ∀x:A. B[x]
, 
and: P ∧ Q
, 
cand: A c∧ B
, 
implies: P 
⇒ Q
, 
exists: ∃x:A. B[x]
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
nat: ℕ
, 
so_apply: x[s]
, 
int_upper: {i...}
, 
ge: i ≥ j 
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
uimplies: b supposing a
, 
not: ¬A
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
false: False
, 
top: Top
, 
rless: x < y
, 
sq_exists: ∃x:A [B[x]]
, 
nat_plus: ℕ+
, 
rneq: x ≠ y
, 
guard: {T}
, 
so_lambda: λ2x.t[x]
, 
series-converges: Σn.x[n]↓
, 
series-sum: Σn.x[n] = a
, 
converges: x[n]↓ as n→∞
, 
subtype_rel: A ⊆r B
, 
le: A ≤ B
, 
less_than': less_than'(a;b)
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
cauchy: cauchy(n.x[n])
, 
sq_stable: SqStable(P)
, 
squash: ↓T
, 
rdiv: (x/y)
, 
uiff: uiff(P;Q)
, 
req_int_terms: t1 ≡ t2
, 
converges-to: lim n→∞.x[n] = y
, 
rleq: x ≤ y
, 
rnonneg: rnonneg(x)
, 
rev_uimplies: rev_uimplies(P;Q)
, 
rge: x ≥ y
, 
subtract: n - m
, 
true: True
, 
int_seg: {i..j-}
, 
lelt: i ≤ j < k
, 
pointwise-rleq: x[k] ≤ y[k] for k ∈ [n,m]
, 
sq_type: SQType(T)
, 
real: ℝ
Lemmas referenced : 
real_wf, 
rless_wf, 
int-to-real_wf, 
istype-nat, 
istype-int_upper, 
int_upper_properties, 
nat_properties, 
decidable__le, 
full-omega-unsat, 
intformand_wf, 
intformnot_wf, 
intformle_wf, 
itermConstant_wf, 
itermVar_wf, 
istype-int, 
int_formula_prop_and_lemma, 
istype-void, 
int_formula_prop_not_lemma, 
int_formula_prop_le_lemma, 
int_term_value_constant_lemma, 
int_term_value_var_lemma, 
int_formula_prop_wf, 
istype-le, 
nat_plus_properties, 
rleq_wf, 
rsub_wf, 
rdiv_wf, 
itermAdd_wf, 
int_term_value_add_lemma, 
converges-to_wf, 
rmul_wf, 
series-diverges_wf, 
converges-iff-cauchy-ext, 
rsum_wf, 
int_seg_subtype_nat, 
istype-false, 
int_seg_wf, 
nat_plus_wf, 
small-reciprocal-real, 
rless-int, 
decidable__lt, 
intformless_wf, 
int_formula_prop_less_lemma, 
rmul_preserves_rless, 
itermSubtract_wf, 
itermMultiply_wf, 
rinv_wf2, 
sq_stable__rless, 
rless_functionality, 
req_transitivity, 
rmul-rinv3, 
req-iff-rsub-is-0, 
real_polynomial_null, 
real_term_value_sub_lemma, 
real_term_value_mul_lemma, 
real_term_value_const_lemma, 
real_term_value_var_lemma, 
int_term_value_mul_lemma, 
istype-less_than, 
sq_stable__all, 
nat_wf, 
le_wf, 
rabs_wf, 
sq_stable__rleq, 
le_witness_for_triv, 
imax_wf, 
sq_stable__less_than, 
intformeq_wf, 
int_formula_prop_eq_lemma, 
imax_ub, 
rleq_functionality_wrt_implies, 
rleq_weakening_equal, 
rleq_weakening, 
radd_wf, 
r-triangle-inequality2, 
rless_functionality_wrt_implies, 
rleq_functionality, 
rabs-difference-symmetry, 
req_weakening, 
radd_functionality_wrt_rleq, 
radd-rdiv, 
rdiv_functionality, 
radd-int, 
req-int-fractions, 
decidable__equal_int, 
rless_transitivity2, 
not-le-2, 
sq_stable__le, 
condition-implies-le, 
minus-add, 
minus-one-mul, 
zero-add, 
minus-one-mul-top, 
add-associates, 
add-swap, 
add-commutes, 
add_functionality_wrt_le, 
add-zero, 
le-add-cancel, 
rabs_functionality, 
rsum-difference, 
rsum_functionality_wrt_rleq, 
subtype_rel_function, 
subtype_rel_self, 
subtract_wf, 
int_seg_properties, 
int_term_value_subtract_lemma, 
subtract-add-cancel, 
rmul_preserves_rleq, 
rmul_preserves_rleq2, 
rleq_weakening_rless, 
rminus_wf, 
itermMinus_wf, 
radd_functionality, 
rmul_functionality, 
rmul-rinv, 
real_term_value_add_lemma, 
real_term_value_minus_lemma, 
squash_wf, 
true_wf, 
iff_weakening_equal, 
rsum_nonneg, 
rabs-of-nonneg, 
rleq_transitivity, 
rsum_linearity2, 
upper_subtype_nat, 
le_transitivity, 
add-subtract-cancel, 
rsum-telescopes2, 
rabs-bounds, 
rinv-mul-as-rdiv, 
rsum-zero-req, 
rleq-int-fractions2, 
radd-preserves-rleq, 
ge_wf, 
subtract-1-ge-0, 
subtype_base_sq, 
int_subtype_base, 
trivial-int-eq1, 
comparison-test-for-divergence, 
series-diverges-rmul, 
rmul-is-positive, 
rmul-nonneg-case1, 
series-diverges-tail
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
cut, 
sqequalHypSubstitution, 
productElimination, 
thin, 
sqequalRule, 
productIsType, 
setIsType, 
universeIsType, 
introduction, 
extract_by_obid, 
hypothesis, 
isectElimination, 
natural_numberEquality, 
hypothesisEquality, 
functionIsType, 
setElimination, 
rename, 
applyEquality, 
dependent_set_memberEquality_alt, 
dependent_functionElimination, 
unionElimination, 
independent_isectElimination, 
approximateComputation, 
independent_functionElimination, 
dependent_pairFormation_alt, 
lambdaEquality_alt, 
int_eqEquality, 
isect_memberEquality_alt, 
voidElimination, 
independent_pairFormation, 
because_Cache, 
addEquality, 
inrFormation_alt, 
closedConclusion, 
inhabitedIsType, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
multiplyEquality, 
functionEquality, 
equalityTransitivity, 
equalitySymmetry, 
functionIsTypeImplies, 
dependent_set_memberFormation_alt, 
applyLambdaEquality, 
equalityIstype, 
inlFormation_alt, 
minusEquality, 
promote_hyp, 
instantiate, 
universeEquality, 
intWeakElimination, 
cumulativity, 
intEquality
Latex:
\mforall{}a,x:\mBbbN{}  {}\mrightarrow{}  \mBbbR{}.
    ((lim  n\mrightarrow{}\minfty{}.a[n]  *  x[n]  =  r0
    {}\mRightarrow{}  (\mexists{}c:\{c:\mBbbR{}|  r0  <  c\} 
              \mexists{}N:\mBbbN{}
                ((\mforall{}n:\{N...\}.  ((r0  <  a[n])  \mwedge{}  (r0  <  x[n])))
                \mwedge{}  (\mforall{}n:\{N...\}.  ((r0  <  a[n])  \mwedge{}  (c  \mleq{}  ((a[n]  *  x[n]/x[n  +  1])  -  a[n  +  1]))))))
    {}\mRightarrow{}  \mSigma{}n.x[n]\mdownarrow{})
    \mwedge{}  ((\mexists{}N:\mBbbN{}
              ((\mforall{}n:\{N...\}.  ((r0  <  a[n])  \mwedge{}  (r0  <  x[n])))
              \mwedge{}  (\mforall{}n:\{N...\}.  (((a[n]  *  x[n]/x[n  +  1])  -  a[n  +  1])  \mleq{}  r0))
              \mwedge{}  \mSigma{}n.(r1/a[N  +  n])\muparrow{}))
        {}\mRightarrow{}  \mSigma{}n.x[n]\muparrow{}))
Date html generated:
2019_10_29-AM-10_27_35
Last ObjectModification:
2018_12_13-PM-02_06_23
Theory : reals
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