Nuprl Lemma : strictly-increasing-on-closed-interval2
∀a,b:ℝ. ∀f:[a, b] ⟶ℝ.
  ((∀x,y:{x:ℝ| x ∈ [a, b]} .  ((x = y) 
⇒ (f[x] = f[y])))
  
⇒ f[x] strictly-increasing for x ∈ (a, b)
  
⇒ (∀x:{x:ℝ| x ∈ [a, b]} . ((f[a] ≤ f[x]) ∧ (f[x] ≤ f[b])))
  
⇒ f[x] strictly-increasing for x ∈ [a, b])
Proof
Definitions occuring in Statement : 
strictly-increasing-on-interval: f[x] strictly-increasing for x ∈ I
, 
rfun: I ⟶ℝ
, 
rooint: (l, u)
, 
rccint: [l, u]
, 
i-member: r ∈ I
, 
rleq: x ≤ y
, 
req: x = y
, 
real: ℝ
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
set: {x:A| B[x]} 
Definitions unfolded in proof : 
subtype_rel: A ⊆r B
, 
label: ...$L... t
, 
rfun: I ⟶ℝ
, 
so_apply: x[s]
, 
so_lambda: λ2x.t[x]
, 
prop: ℙ
, 
uimplies: b supposing a
, 
guard: {T}
, 
uall: ∀[x:A]. B[x]
, 
cand: A c∧ B
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
top: Top
, 
subinterval: I ⊆ J 
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
increasing-on-interval: f[x] increasing for x ∈ I
, 
false: False
, 
or: P ∨ Q
, 
not: ¬A
, 
stable: Stable{P}
, 
strictly-increasing-on-interval: f[x] strictly-increasing for x ∈ I
, 
squash: ↓T
, 
sq_stable: SqStable(P)
Lemmas referenced : 
rfun_wf, 
req_wf, 
subtype_rel_sets, 
rooint_wf, 
strictly-increasing-on-interval_wf, 
rleq_transitivity, 
rleq_weakening_equal, 
rleq_wf, 
rccint_wf, 
i-member_wf, 
all_wf, 
real_wf, 
rless_wf, 
rleq_weakening_rless, 
member_rccint_lemma, 
member_rooint_lemma, 
strictly-increasing-on-closed-interval, 
set_wf, 
minimal-not-not-excluded-middle, 
minimal-double-negation-hyp-elim, 
not_wf, 
or_wf, 
false_wf, 
stable__rleq, 
rless_transitivity2, 
rless_transitivity1, 
rleq_weakening, 
rleq_antisymmetry, 
not-rless, 
req_inversion, 
sq_stable__rleq
Rules used in proof : 
functionEquality, 
dependent_set_memberEquality, 
because_Cache, 
applyEquality, 
rename, 
setElimination, 
lambdaEquality, 
setEquality, 
independent_functionElimination, 
productEquality, 
independent_pairFormation, 
independent_isectElimination, 
isectElimination, 
productElimination, 
voidEquality, 
voidElimination, 
isect_memberEquality, 
sqequalRule, 
hypothesisEquality, 
thin, 
dependent_functionElimination, 
sqequalHypSubstitution, 
hypothesis, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
extract_by_obid, 
introduction, 
cut, 
unionElimination, 
imageElimination, 
baseClosed, 
imageMemberEquality
Latex:
\mforall{}a,b:\mBbbR{}.  \mforall{}f:[a,  b]  {}\mrightarrow{}\mBbbR{}.
    ((\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  [a,  b]\}  .    ((x  =  y)  {}\mRightarrow{}  (f[x]  =  f[y])))
    {}\mRightarrow{}  f[x]  strictly-increasing  for  x  \mmember{}  (a,  b)
    {}\mRightarrow{}  (\mforall{}x:\{x:\mBbbR{}|  x  \mmember{}  [a,  b]\}  .  ((f[a]  \mleq{}  f[x])  \mwedge{}  (f[x]  \mleq{}  f[b])))
    {}\mRightarrow{}  f[x]  strictly-increasing  for  x  \mmember{}  [a,  b])
Date html generated:
2017_10_03-PM-00_29_43
Last ObjectModification:
2017_07_30-PM-08_56_24
Theory : reals
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