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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