Nuprl Lemma : strict-monotonic-is-locally-non-constant

∀I:Interval. ∀f:I ⟶ℝ.
  (((∀x,y:{x:ℝ| x ∈ I} .  ((x < y) ⇒ ((f x) < (f y)))) ∨ (∀x,y:{x:ℝ| x ∈ I} .  ((x < y) ⇒ ((f y) < (f x)))))
  ⇒ (∀a,b:{x:ℝ| x ∈ I} . ∀x:ℝ.  locally-non-constant(f;a;b;x)))


Proof




Definitions occuring in Statement :  locally-non-constant: locally-non-constant(f;a;b;c),  rfun: I ⟶ℝ,  i-member: r ∈ I,  interval: Interval,  rless: x < y,  real: ℝ,  all: ∀x:A. B[x],  implies: P ⇒ Q,  or: P ∨ Q,  set: {x:A| B[x]} ,  apply: f a
Definitions unfolded in proof :  rfun: I ⟶ℝ,  so_apply: x[s],  so_lambda: λ2x.t[x],  uall: ∀[x:A]. B[x],  prop: ℙ,  member: t ∈ T,  implies: P ⇒ Q,  all: ∀x:A. B[x],  or: P ∨ Q,  uimplies: b supposing a,  guard: {T},  rneq: x ≠ y,  locally-non-constant: locally-non-constant(f;a;b;c),  squash: ↓T,  sq_stable: SqStable(P),  and: P ∧ Q,  exists: ∃x:A. B[x],  r-ap: f(x)
Lemmas referenced :  interval_wf,  rfun_wf,  rless_wf,  all_wf,  or_wf,  i-member_wf,  set_wf,  real_wf,  rless_transitivity2,  rleq_weakening_rless,  rless_transitivity1,  i-member-between,  rleq_wf,  rneq-cases,  rleq_transitivity,  sq_stable__i-member,  r-ap_wf,  rneq_wf,  rleq_weakening_equal
Rules used in proof :  dependent_set_memberEquality,  applyEquality,  functionEquality,  because_Cache,  rename,  setElimination,  setEquality,  hypothesisEquality,  lambdaEquality,  sqequalRule,  thin,  isectElimination,  sqequalHypSubstitution,  hypothesis,  extract_by_obid,  introduction,  cut,  lambdaFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution,  inrFormation,  inlFormation,  unionElimination,  independent_isectElimination,  independent_functionElimination,  dependent_functionElimination,  imageElimination,  baseClosed,  imageMemberEquality,  productEquality,  independent_pairFormation,  dependent_pairFormation

Latex:
\mforall{}I:Interval.  \mforall{}f:I  {}\mrightarrow{}\mBbbR{}.
    (((\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  I\}  .    ((x  <  y)  {}\mRightarrow{}  ((f  x)  <  (f  y))))
    \mvee{}  (\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  I\}  .    ((x  <  y)  {}\mRightarrow{}  ((f  y)  <  (f  x)))))
    {}\mRightarrow{}  (\mforall{}a,b:\{x:\mBbbR{}|  x  \mmember{}  I\}  .  \mforall{}x:\mBbbR{}.    locally-non-constant(f;a;b;x)))



Date html generated: 2017_10_03-AM-10_31_43
Last ObjectModification: 2017_07_29-PM-00_45_02

Theory : reals


Home Index