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

I:Interval. ∀f:I ⟶ℝ.
  (((∀x,y:{x:ℝx ∈ I} .  ((x < y)  ((f x) < (f y)))) ∨ (∀x,y:{x:ℝx ∈ I} .  ((x < y)  ((f y) < (f x)))))
   (∀a,b:{x:ℝx ∈ 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: all: x:A. B[x] implies:  Q or: P ∨ Q set: {x:A| B[x]}  apply: a
Definitions unfolded in proof :  rfun: I ⟶ℝ so_apply: x[s] so_lambda: λ2x.t[x] uall: [x:A]. B[x] prop: member: t ∈ T implies:  Q all: x:A. B[x] or: P ∨ Q uimplies: 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


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