Nuprl Lemma : rabs-rlog-difference-bound

∀x,y:ℝ.  ((r0 < x) ⇒ (r0 < y) ⇒ (|rlog(y) - rlog(x)| ≤ (|y - x|/rmin(x;y))))


Proof




Definitions occuring in Statement :  rlog: rlog(x),  rdiv: (x/y),  rleq: x ≤ y,  rless: x < y,  rabs: |x|,  rmin: rmin(x;y),  rsub: x - y,  int-to-real: r(n),  real: ℝ,  all: ∀x:A. B[x],  implies: P ⇒ Q,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  iff: P ⇐⇒ Q,  and: P ∧ Q,  cand: A c∧ B,  uall: ∀[x:A]. B[x],  iproper: iproper(I),  i-finite: i-finite(I),  rciint: [l, ∞),  isl: isl(x),  assert: ↑b,  ifthenelse: if b then t else f fi ,  btrue: tt,  bfalse: ff,  false: False,  prop: ℙ,  so_lambda: λ2x.t[x],  so_apply: x[s],  uimplies: b supposing a,  rneq: x ≠ y,  guard: {T},  or: P ∨ Q,  rfun: I ⟶ℝ,  top: Top,  sq_stable: SqStable(P),  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q),  squash: ↓T,  subinterval: I ⊆ J ,  rev_implies: P ⇐ Q,  le: A ≤ B,  less_than': less_than'(a;b),  not: ¬A,  rge: x ≥ y
Lemmas referenced :  rmin_strict_ub,  mean-value-for-bounded-derivative,  rciint_wf,  rmin_wf,  true_wf,  false_wf,  rdiv_wf,  int-to-real_wf,  rless_wf,  real_wf,  rlog_wf,  member_rciint_lemma,  rless_transitivity1,  i-member_wf,  rleq_wf,  sq_stable__req,  req_functionality,  rdiv_functionality,  req_weakening,  req_wf,  set_wf,  derivative-rlog,  member_roiint_lemma,  derivative_functionality_wrt_subinterval,  roiint_wf,  sq_stable__rless,  sq_stable__rleq,  rabs_wf,  rmul_preserves_rleq,  rmul_wf,  rleq-int,  rleq_functionality,  rabs-of-nonneg,  uiff_transitivity,  rmul-rdiv-cancel2,  rmul-zero-both,  req_inversion,  rmul-assoc,  rmul_functionality,  rmul_comm,  rmul-ac,  rmul-rdiv-cancel,  rmul-one-both,  rsub_wf,  rmin-rleq,  equal_wf,  rleq_functionality_wrt_implies,  rleq_weakening_equal
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  because_Cache,  productElimination,  independent_functionElimination,  hypothesis,  independent_pairFormation,  isectElimination,  sqequalRule,  voidElimination,  productEquality,  natural_numberEquality,  independent_isectElimination,  inrFormation,  lambdaEquality,  setElimination,  rename,  isect_memberEquality,  voidEquality,  dependent_set_memberEquality,  setEquality,  imageMemberEquality,  baseClosed,  imageElimination,  equalityTransitivity,  equalitySymmetry

Latex:
\mforall{}x,y:\mBbbR{}.    ((r0  <  x)  {}\mRightarrow{}  (r0  <  y)  {}\mRightarrow{}  (|rlog(y)  -  rlog(x)|  \mleq{}  (|y  -  x|/rmin(x;y))))



Date html generated: 2017_10_04-PM-10_26_09
Last ObjectModification: 2017_07_28-AM-08_49_54

Theory : reals_2


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