Nuprl Lemma : arctan-poly-approx
∀[x:ℝ]. ∀[k:ℕ].  (|arctangent(x) - arctan-poly(x;k)| ≤ (|x|^(2 * k) + 3/r((2 * k) + 3)))
Proof
Definitions occuring in Statement : 
arctan-poly: arctan-poly(x;k)
, 
arctangent: arctangent(x)
, 
rdiv: (x/y)
, 
rleq: x ≤ y
, 
rabs: |x|
, 
rnexp: x^k1
, 
rsub: x - y
, 
int-to-real: r(n)
, 
real: ℝ
, 
nat: ℕ
, 
uall: ∀[x:A]. B[x]
, 
multiply: n * m
, 
add: n + m
, 
natural_number: $n
Definitions unfolded in proof : 
absval: |i|
, 
rdiv: (x/y)
, 
pointwise-req: x[k] = y[k] for k ∈ [n,m]
, 
so_apply: x[s]
, 
assert: ↑b
, 
bnot: ¬bb
, 
bfalse: ff
, 
ifthenelse: if b then t else f fi 
, 
btrue: tt
, 
it: ⋅
, 
unit: Unit
, 
bool: 𝔹
, 
sq_type: SQType(T)
, 
true: True
, 
lelt: i ≤ j < k
, 
nequal: a ≠ b ∈ T 
, 
int_seg: {i..j-}
, 
int_nzero: ℤ-o
, 
so_lambda: λ2x.t[x]
, 
arctan-poly: arctan-poly(x;k)
, 
req_int_terms: t1 ≡ t2
, 
uiff: uiff(P;Q)
, 
rge: x ≥ y
, 
rev_uimplies: rev_uimplies(P;Q)
, 
squash: ↓T
, 
sq_stable: SqStable(P)
, 
real: ℝ
, 
sq_exists: ∃x:A [B[x]]
, 
rless: x < y
, 
stable: Stable{P}
, 
subtype_rel: A ⊆r B
, 
rev_implies: P 
⇐ Q
, 
iff: P 
⇐⇒ Q
, 
guard: {T}
, 
rneq: x ≠ y
, 
prop: ℙ
, 
top: Top
, 
exists: ∃x:A. B[x]
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
uimplies: b supposing a
, 
or: P ∨ Q
, 
decidable: Dec(P)
, 
ge: i ≥ j 
, 
nat_plus: ℕ+
, 
nat: ℕ
, 
false: False
, 
implies: P 
⇒ Q
, 
not: ¬A
, 
and: P ∧ Q
, 
le: A ≤ B
, 
all: ∀x:A. B[x]
, 
rnonneg: rnonneg(x)
, 
rleq: x ≤ y
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
Lemmas referenced : 
minus-zero, 
rneq_wf, 
rinv-mul-as-rdiv, 
rabs-int, 
rmul_comm, 
rnexp0, 
int-rdiv_functionality, 
arctangent0, 
rmul-zero-both, 
less_than_wf, 
rsum-zero-req, 
arctangent_functionality, 
not-rless, 
rleq_antisymmetry, 
rabs-of-nonpos, 
rabs_functionality, 
arctangent-rminus, 
rsub_functionality, 
iff_weakening_equal, 
subtype_rel_self, 
rabs-rminus, 
squash_wf, 
rminus-rminus, 
rnexp-rminus, 
assert-isOdd, 
isOdd_wf, 
real_term_value_var_lemma, 
real_term_value_mul_lemma, 
rmul-rinv3, 
req_transitivity, 
rminus_functionality, 
int-rdiv-req, 
rsum-rminus, 
req_inversion, 
req_functionality, 
rinv_wf2, 
rmul_wf, 
rmul_preserves_req, 
rsum_functionality, 
int_seg_wf, 
neg_assert_of_eq_int, 
assert-bnot, 
bool_subtype_base, 
bool_cases_sqequal, 
equal_wf, 
eqff_to_assert, 
assert_of_eq_int, 
eqtt_to_assert, 
bool_wf, 
true_wf, 
subtype_base_sq, 
eq_int_wf, 
nequal_wf, 
int_subtype_base, 
equal-wf-base, 
int_formula_prop_eq_lemma, 
intformeq_wf, 
int_seg_properties, 
int-rdiv_wf, 
rsum_wf, 
real_term_value_minus_lemma, 
real_term_value_const_lemma, 
real_term_value_sub_lemma, 
real_polynomial_null, 
req-iff-rsub-is-0, 
itermMinus_wf, 
itermSubtract_wf, 
rleq_weakening, 
rminus_functionality_wrt_rleq, 
rminus_wf, 
rabs-of-nonneg, 
rnexp_functionality, 
rdiv_functionality, 
req_weakening, 
rleq_functionality, 
rleq_weakening_equal, 
rleq_functionality_wrt_implies, 
sq_stable__less_than, 
rleq_weakening_rless, 
arctan-poly-approx-1, 
minimal-not-not-excluded-middle, 
minimal-double-negation-hyp-elim, 
rleq_wf, 
not_wf, 
or_wf, 
false_wf, 
stable__rleq, 
real_wf, 
nat_wf, 
nat_plus_wf, 
arctan-poly_wf, 
arctangent_wf, 
rless_wf, 
int_formula_prop_less_lemma, 
intformless_wf, 
decidable__lt, 
rless-int, 
int-to-real_wf, 
rabs_wf, 
le_wf, 
int_formula_prop_wf, 
int_term_value_var_lemma, 
int_term_value_mul_lemma, 
int_term_value_add_lemma, 
int_term_value_constant_lemma, 
int_formula_prop_le_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_and_lemma, 
itermVar_wf, 
itermMultiply_wf, 
itermAdd_wf, 
itermConstant_wf, 
intformle_wf, 
intformnot_wf, 
intformand_wf, 
full-omega-unsat, 
decidable__le, 
nat_properties, 
nat_plus_properties, 
rnexp_wf, 
rdiv_wf, 
rsub_wf, 
less_than'_wf
Rules used in proof : 
universeEquality, 
promote_hyp, 
equalityElimination, 
cumulativity, 
instantiate, 
addLevel, 
remainderEquality, 
closedConclusion, 
baseApply, 
imageElimination, 
baseClosed, 
imageMemberEquality, 
lambdaFormation, 
functionEquality, 
equalitySymmetry, 
equalityTransitivity, 
axiomEquality, 
minusEquality, 
inrFormation, 
independent_pairFormation, 
voidEquality, 
voidElimination, 
isect_memberEquality, 
intEquality, 
int_eqEquality, 
dependent_pairFormation, 
independent_functionElimination, 
approximateComputation, 
independent_isectElimination, 
unionElimination, 
hypothesis, 
rename, 
setElimination, 
natural_numberEquality, 
multiplyEquality, 
addEquality, 
dependent_set_memberEquality, 
applyEquality, 
isectElimination, 
extract_by_obid, 
because_Cache, 
independent_pairEquality, 
productElimination, 
hypothesisEquality, 
thin, 
dependent_functionElimination, 
lambdaEquality, 
sqequalHypSubstitution, 
sqequalRule, 
cut, 
introduction, 
isect_memberFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}[x:\mBbbR{}].  \mforall{}[k:\mBbbN{}].    (|arctangent(x)  -  arctan-poly(x;k)|  \mleq{}  (|x|\^{}(2  *  k)  +  3/r((2  *  k)  +  3)))
Date html generated:
2018_05_22-PM-03_04_48
Last ObjectModification:
2018_05_20-PM-11_15_16
Theory : reals_2
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