Nuprl Lemma : atan-small_wf

∀[x:ℝ]. atan-small(x) ∈ {y:ℝ| arctangent(x) = y}  supposing |x| ≤ (r1/r(2))


Proof




Definitions occuring in Statement :  atan-small: atan-small(x),  arctangent: arctangent(x),  rdiv: (x/y),  rleq: x ≤ y,  rabs: |x|,  req: x = y,  int-to-real: r(n),  real: ℝ,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  member: t ∈ T,  set: {x:A| B[x]} ,  natural_number: $n
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  atan-small: atan-small(x),  rneq: x ≠ y,  guard: {T},  or: P ∨ Q,  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ Q,  implies: P ⇒ Q,  less_than: a < b,  squash: ↓T,  less_than': less_than'(a;b),  true: True,  prop: ℙ,  subtype_rel: A ⊆r B,  int_upper: {i...},  decidable: Dec(P),  not: ¬A,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  top: Top,  so_lambda: λ2x.t[x],  so_apply: x[s],  sq_stable: SqStable(P)
Lemmas referenced :  atan_wf,  atan-size-bound_wf,  rleq_wf,  rabs_wf,  rdiv_wf,  rless-int,  rless_wf,  int-to-real_wf,  int_upper_properties,  decidable__lt,  full-omega-unsat,  intformand_wf,  intformnot_wf,  intformless_wf,  itermConstant_wf,  itermVar_wf,  intformle_wf,  int_formula_prop_and_lemma,  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,  real_wf,  set_wf,  int_upper_wf,  sq_stable__rleq,  equal_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalRule,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  dependent_set_memberEquality,  hypothesisEquality,  hypothesis,  because_Cache,  independent_isectElimination,  inrFormation,  dependent_functionElimination,  productElimination,  independent_functionElimination,  independent_pairFormation,  natural_numberEquality,  imageMemberEquality,  baseClosed,  applyEquality,  lambdaEquality,  setElimination,  rename,  setEquality,  unionElimination,  approximateComputation,  dependent_pairFormation,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  lambdaFormation,  imageElimination

Latex:
\mforall{}[x:\mBbbR{}].  atan-small(x)  \mmember{}  \{y:\mBbbR{}|  arctangent(x)  =  y\}    supposing  |x|  \mleq{}  (r1/r(2))



Date html generated: 2018_05_22-PM-03_06_49
Last ObjectModification: 2017_10_26-PM-10_45_32

Theory : reals_2


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