Nuprl Lemma : strict-increasing-implies-inv-strict-increasing
∀[I:Interval]. ∀[f:I ⟶ℝ].
  (∀x,y:{x:ℝ| x ∈ I} .  (((f x) < (f y)) 
⇒ (x < y))) supposing 
     ((∀x,y:{x:ℝ| x ∈ I} .  ((x < y) 
⇒ ((f x) < (f y)))) and 
     (∀x,y:{x:ℝ| x ∈ I} .  ((x = y) 
⇒ ((f x) = (f y)))))
Proof
Definitions occuring in Statement : 
rfun: I ⟶ℝ
, 
i-member: r ∈ I
, 
interval: Interval
, 
rless: x < y
, 
req: x = y
, 
real: ℝ
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
set: {x:A| B[x]} 
, 
apply: f a
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
rfun: I ⟶ℝ
, 
prop: ℙ
, 
sq_stable: SqStable(P)
, 
squash: ↓T
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
rneq: x ≠ y
, 
or: P ∨ Q
, 
guard: {T}
, 
false: False
Lemmas referenced : 
real-fun-implies-sfun-general, 
req_witness, 
i-member_wf, 
req_wf, 
real_wf, 
sq_stable__rless, 
rless_wf, 
set_wf, 
all_wf, 
rfun_wf, 
interval_wf, 
rless_transitivity2, 
rleq_weakening_rless, 
rless_irreflexivity
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
hypothesis, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
sqequalRule, 
lambdaEquality, 
dependent_functionElimination, 
applyEquality, 
setElimination, 
rename, 
dependent_set_memberEquality, 
because_Cache, 
independent_functionElimination, 
setEquality, 
independent_isectElimination, 
lambdaFormation, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
functionEquality, 
inlFormation, 
unionElimination, 
voidElimination
Latex:
\mforall{}[I:Interval].  \mforall{}[f:I  {}\mrightarrow{}\mBbbR{}].
    (\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  I\}  .    (((f  x)  <  (f  y))  {}\mRightarrow{}  (x  <  y)))  supposing 
          ((\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  I\}  .    ((x  <  y)  {}\mRightarrow{}  ((f  x)  <  (f  y))))  and 
          (\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  I\}  .    ((x  =  y)  {}\mRightarrow{}  ((f  x)  =  (f  y)))))
Date html generated:
2017_10_03-AM-09_57_15
Last ObjectModification:
2017_08_31-PM-01_21_40
Theory : reals
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