Nuprl Lemma : arctangent-reduction

∀B:{B:ℝ| r0 < B} . ∀x:{x:ℝ| (r(-1)/B) < x} .  (arctangent(x) = (arctangent(B) + arctangent((x - B/r1 + (x * B)))))


Proof




Definitions occuring in Statement :  arctangent: arctangent(x),  rdiv: (x/y),  rless: x < y,  rsub: x - y,  req: x = y,  rmul: a * b,  radd: a + b,  int-to-real: r(n),  real: ℝ,  all: ∀x:A. B[x],  set: {x:A| B[x]} ,  minus: -n,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  member: t ∈ T,  uall: ∀[x:A]. B[x],  uimplies: b supposing a,  rneq: x ≠ y,  guard: {T},  or: P ∨ Q,  sq_stable: SqStable(P),  implies: P ⇒ Q,  squash: ↓T,  prop: ℙ,  iff: P ⇐⇒ Q,  and: P ∧ Q,  uiff: uiff(P;Q),  nat: ℕ,  decidable: Dec(P),  not: ¬A,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  top: Top,  false: False,  rev_implies: P ⇐ Q,  less_than: a < b,  less_than': less_than'(a;b),  true: True,  rdiv: (x/y),  req_int_terms: t1 ≡ t2,  rge: x ≥ y,  so_lambda: λ2x.t[x],  rfun: I ⟶ℝ,  so_apply: x[s],  rfun-eq: rfun-eq(I;f;g),  r-ap: f(x),  rev_uimplies: rev_uimplies(P;Q),  subtype_rel: A ⊆r B,  rless: x < y,  sq_exists: ∃x:A [B[x]],  i-member: r ∈ I,  roiint: (l, ∞),  concave-on: concave-on(I;x.f[x]),  cand: A c∧ B,  nat_plus: ℕ+,  rat_term_to_real: rat_term_to_real(f;t),  rtermDivide: num "/" denom,  rat_term_ind: rat_term_ind,  rtermConstant: "const",  rtermVar: rtermVar(var),  pi1: fst(t),  rtermMultiply: left "*" right,  pi2: snd(t)
Lemmas referenced :  real_wf,  rless_wf,  rdiv_wf,  int-to-real_wf,  sq_stable__rless,  radd_wf,  rmul_wf,  rmul_preserves_rless,  rnexp2-nonneg,  derivative-arctangent,  rinv_wf2,  rminus_wf,  itermSubtract_wf,  itermMultiply_wf,  itermConstant_wf,  itermVar_wf,  itermMinus_wf,  rless-implies-rless,  rsub_wf,  itermAdd_wf,  req-iff-rsub-is-0,  rnexp_wf,  decidable__le,  full-omega-unsat,  intformnot_wf,  intformle_wf,  istype-int,  int_formula_prop_not_lemma,  istype-void,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_formula_prop_wf,  istype-le,  trivial-rless-radd,  rless-int,  rless_functionality,  req_transitivity,  rminus_functionality,  rmul-rinv,  real_polynomial_null,  real_term_value_sub_lemma,  real_term_value_mul_lemma,  real_term_value_const_lemma,  real_term_value_var_lemma,  real_term_value_minus_lemma,  real_term_value_add_lemma,  rless_functionality_wrt_implies,  rleq_weakening_equal,  radd_functionality_wrt_rleq,  antiderivatives-equal,  roiint_wf,  iproper-roiint,  i-member_wf,  arctangent_wf,  member_roiint_lemma,  riiint_wf,  req_weakening,  subinterval-riiint,  derivative_functionality2,  rnexp-positive,  arctangent-chain-rule,  req_functionality,  rdiv_functionality,  rnexp_functionality,  radd_functionality,  rmul_functionality,  req_wf,  derivative-rdiv,  istype-top,  subtype_rel_dep_function,  top_wf,  concave-positive-nonzero-on,  rleq_weakening,  rccint_wf,  member_riiint_lemma,  true_wf,  istype-true,  derivative-sub,  derivative-id,  derivative-const,  derivative-add,  derivative-const-mul2,  rmul-is-positive,  nat_plus_properties,  sq_stable__rneq,  rmul_comm,  derivative_functionality,  rnexp2,  derivative-add-const,  rdiv-rdiv,  rmul-rinv3,  squash_wf,  subtype_rel_self,  iff_weakening_equal,  req_inversion,  rless_transitivity1,  assert-rat-term-eq2,  rtermDivide_wf,  rtermVar_wf,  rtermMultiply_wf,  rtermConstant_wf,  square-nonneg,  rmul_preserves_req,  uiff_transitivity,  arctangent_functionality,  arctangent0
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  setIsType,  universeIsType,  cut,  introduction,  extract_by_obid,  hypothesis,  sqequalHypSubstitution,  isectElimination,  thin,  closedConclusion,  minusEquality,  natural_numberEquality,  setElimination,  rename,  because_Cache,  independent_isectElimination,  sqequalRule,  inrFormation_alt,  dependent_functionElimination,  hypothesisEquality,  independent_functionElimination,  imageMemberEquality,  baseClosed,  imageElimination,  productElimination,  inhabitedIsType,  dependent_set_memberEquality_alt,  unionElimination,  approximateComputation,  dependent_pairFormation_alt,  lambdaEquality_alt,  isect_memberEquality_alt,  voidElimination,  independent_pairFormation,  int_eqEquality,  equalityTransitivity,  equalitySymmetry,  applyEquality,  setEquality,  inlFormation_alt,  productIsType,  equalityIstype,  instantiate,  universeEquality

Latex:
\mforall{}B:\{B:\mBbbR{}|  r0  <  B\}  .  \mforall{}x:\{x:\mBbbR{}|  (r(-1)/B)  <  x\}  .
    (arctangent(x)  =  (arctangent(B)  +  arctangent((x  -  B/r1  +  (x  *  B)))))



Date html generated: 2019_10_31-AM-06_08_00
Last ObjectModification: 2019_04_03-AM-00_28_15

Theory : reals_2


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