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
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