Nuprl Lemma : cosine-approx-for-small

∀a:{2...}. ∀N:ℕ+. ∀x:{x:ℝ| |x| ≤ (r1/r(a))} .  (∃z:ℤ [(|cosine(x) - (r(z)/r(2 * N))| ≤ (r(2)/r(N)))])


Proof




Definitions occuring in Statement :  cosine: cosine(x),  rdiv: (x/y),  rleq: x ≤ y,  rabs: |x|,  rsub: x - y,  int-to-real: r(n),  real: ℝ,  int_upper: {i...},  nat_plus: ℕ+,  all: ∀x:A. B[x],  sq_exists: ∃x:A [B[x]],  set: {x:A| B[x]} ,  multiply: n * m,  natural_number: $n,  int: ℤ
Definitions unfolded in proof :  all: ∀x:A. B[x],  uall: ∀[x:A]. B[x],  member: t ∈ T,  nat_plus: ℕ+,  int_upper: {i...},  decidable: Dec(P),  or: P ∨ Q,  uimplies: b supposing a,  not: ¬A,  implies: P ⇒ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  top: Top,  and: P ∧ Q,  prop: ℙ,  uiff: uiff(P;Q),  rneq: x ≠ y,  guard: {T},  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  less_than: a < b,  squash: ↓T,  less_than': less_than'(a;b),  true: True,  sq_stable: SqStable(P),  sq_exists: ∃x:A [B[x]],  nat: ℕ,  ge: i ≥ j ,  subtype_rel: A ⊆r B,  rev_uimplies: rev_uimplies(P;Q),  rge: x ≥ y,  rless: x < y,  rdiv: (x/y),  req_int_terms: t1 ≡ t2
Lemmas referenced :  rleq-int-fractions,  nat_plus_properties,  int_upper_properties,  decidable__lt,  full-omega-unsat,  intformand_wf,  intformnot_wf,  intformless_wf,  itermConstant_wf,  itermVar_wf,  intformle_wf,  istype-int,  int_formula_prop_and_lemma,  istype-void,  int_formula_prop_not_lemma,  int_formula_prop_less_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_le_lemma,  int_formula_prop_wf,  istype-less_than,  decidable__le,  itermMultiply_wf,  int_term_value_mul_lemma,  sq_stable__rleq,  rabs_wf,  rdiv_wf,  int-to-real_wf,  rless-int,  rless_wf,  rleq_transitivity,  cosine-approx-lemma-ext,  cosine-approx_wf,  rleq_wf,  rsub_wf,  nat_properties,  real_wf,  nat_plus_wf,  istype-int_upper,  cosine_wf,  radd_wf,  rnexp_wf,  itermAdd_wf,  int_term_value_add_lemma,  istype-le,  fact_wf,  exp_wf2,  rneq-int,  intformeq_wf,  int_formula_prop_eq_lemma,  rleq_functionality_wrt_implies,  cosine-poly-approx,  rleq_weakening_equal,  mul_bounds_1b,  mul_nat_plus,  radd_functionality_wrt_rleq,  rleq_functionality,  radd-int-fractions,  req_weakening,  rnexp-rleq,  zero-rleq-rabs,  rnexp-positive,  req_inversion,  rnexp-rdiv,  exp-positive,  rdiv_functionality,  rnexp-one,  rnexp-int,  exp_wf_nat_plus,  rmul_preserves_rleq,  rmul_wf,  rinv_wf2,  itermSubtract_wf,  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_var_lemma,  real_term_value_const_lemma
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  natural_numberEquality,  because_Cache,  dependent_set_memberEquality_alt,  setElimination,  rename,  hypothesisEquality,  hypothesis,  dependent_functionElimination,  unionElimination,  independent_isectElimination,  approximateComputation,  independent_functionElimination,  dependent_pairFormation_alt,  lambdaEquality_alt,  int_eqEquality,  isect_memberEquality_alt,  voidElimination,  sqequalRule,  independent_pairFormation,  universeIsType,  productElimination,  multiplyEquality,  closedConclusion,  inrFormation_alt,  imageMemberEquality,  baseClosed,  imageElimination,  dependent_set_memberFormation_alt,  setIsType,  addEquality,  applyEquality,  inhabitedIsType,  equalityTransitivity,  equalitySymmetry,  applyLambdaEquality,  equalityIstype,  sqequalBase

Latex:
\mforall{}a:\{2...\}.  \mforall{}N:\mBbbN{}\msupplus{}.  \mforall{}x:\{x:\mBbbR{}|  |x|  \mleq{}  (r1/r(a))\}  .    (\mexists{}z:\mBbbZ{}  [(|cosine(x)  -  (r(z)/r(2  *  N))|  \mleq{}  (r(2)/r(N)))]\000C)



Date html generated: 2019_10_29-AM-10_37_33
Last ObjectModification: 2019_02_02-PM-00_33_34

Theory : reals


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