Nuprl Lemma : IVT-from-connected
∀u,v:ℝ. ∀f:[u, v] ⟶ℝ.
  ((u ≤ v)
  
⇒ (∀x,y:{x:ℝ| x ∈ [u, v]} .  ((x = y) 
⇒ (f(x) = f(y))))
  
⇒ (f(u) < r0)
  
⇒ (r0 < f(v))
  
⇒ (∀e:{e:ℝ| r0 < e} . ∃c:{c:ℝ| c ∈ [u, v]} . (|f(c)| < e)))
Proof
Definitions occuring in Statement : 
r-ap: f(x)
, 
rfun: I ⟶ℝ
, 
rccint: [l, u]
, 
i-member: r ∈ I
, 
rleq: x ≤ y
, 
rless: x < y
, 
rabs: |x|
, 
req: x = y
, 
int-to-real: r(n)
, 
real: ℝ
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
implies: P 
⇒ Q
, 
set: {x:A| B[x]} 
, 
natural_number: $n
Definitions unfolded in proof : 
iff: P 
⇐⇒ Q
, 
or: P ∨ Q
, 
not: ¬A
, 
false: False
, 
req_int_terms: t1 ≡ t2
, 
rgt: x > y
, 
rge: x ≥ y
, 
rev_implies: P 
⇐ Q
, 
uiff: uiff(P;Q)
, 
cand: A c∧ B
, 
exists: ∃x:A. B[x]
, 
guard: {T}
, 
squash: ↓T
, 
sq_stable: SqStable(P)
, 
top: Top
, 
and: P ∧ Q
, 
rccint: [l, u]
, 
i-member: r ∈ I
, 
so_apply: x[s]
, 
uimplies: b supposing a
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
uall: ∀[x:A]. B[x]
, 
connected: Connected(X)
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
Lemmas referenced : 
rabs_wf, 
rabs-rless-iff, 
rless-cases, 
real_term_value_minus_lemma, 
real_term_value_const_lemma, 
real_term_value_var_lemma, 
real_term_value_sub_lemma, 
real_polynomial_null, 
rless_functionality_wrt_implies, 
req-iff-rsub-is-0, 
itermMinus_wf, 
itermConstant_wf, 
itermVar_wf, 
itermSubtract_wf, 
rsub_wf, 
rless-implies-rless, 
rleq_weakening_rless, 
rfun_wf, 
rleq_wf, 
req_wf, 
all_wf, 
rleq_weakening_equal, 
int-to-real_wf, 
set_wf, 
rless_transitivity1, 
req_inversion, 
sq_stable__i-member, 
rleq_weakening, 
rless_transitivity2, 
sq_stable__rleq, 
member_rccint_lemma, 
sq_stable__rless, 
rminus_wf, 
r-ap_wf, 
rless_wf, 
real_wf, 
rccint_wf, 
i-member_wf, 
closed-interval-connected
Rules used in proof : 
inlFormation, 
inrFormation, 
unionElimination, 
intEquality, 
int_eqEquality, 
approximateComputation, 
productEquality, 
dependent_set_memberEquality, 
dependent_pairFormation, 
functionEquality, 
natural_numberEquality, 
imageElimination, 
baseClosed, 
imageMemberEquality, 
productElimination, 
voidEquality, 
voidElimination, 
isect_memberEquality, 
independent_pairFormation, 
independent_functionElimination, 
because_Cache, 
setEquality, 
independent_isectElimination, 
rename, 
setElimination, 
lambdaEquality, 
sqequalRule, 
isectElimination, 
hypothesisEquality, 
thin, 
dependent_functionElimination, 
sqequalHypSubstitution, 
hypothesis, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
extract_by_obid, 
introduction, 
cut
Latex:
\mforall{}u,v:\mBbbR{}.  \mforall{}f:[u,  v]  {}\mrightarrow{}\mBbbR{}.
    ((u  \mleq{}  v)
    {}\mRightarrow{}  (\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  [u,  v]\}  .    ((x  =  y)  {}\mRightarrow{}  (f(x)  =  f(y))))
    {}\mRightarrow{}  (f(u)  <  r0)
    {}\mRightarrow{}  (r0  <  f(v))
    {}\mRightarrow{}  (\mforall{}e:\{e:\mBbbR{}|  r0  <  e\}  .  \mexists{}c:\{c:\mBbbR{}|  c  \mmember{}  [u,  v]\}  .  (|f(c)|  <  e)))
Date html generated:
2018_05_22-PM-02_16_48
Last ObjectModification:
2018_05_21-AM-00_31_50
Theory : reals
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