Nuprl Lemma : arctangent-reduction

B:{B:ℝr0 < 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: y req: y rmul: b radd: b int-to-real: r(n) real: 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: supposing a rneq: x ≠ y guard: {T} or: P ∨ Q sq_stable: SqStable(P) implies:  Q squash: T prop: iff: ⇐⇒ Q and: P ∧ Q uiff: uiff(P;Q) nat: decidable: Dec(P) not: ¬A satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] top: Top false: False rev_implies:  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 ⊆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: c∧ B nat_plus: + 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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