Nuprl Lemma : rational-IVT-2
∀a,b:ℤ × ℕ+. ∀f:(ℤ × ℕ+) ⟶ (ℤ × ℕ+).
  ∀[g:{x:ℝ| x ∈ [ratreal(a), ratreal(b)]}  ⟶ ℝ]
    ∃c:{c:ℝ| c ∈ [ratreal(a), ratreal(b)]}  [(g[c] = r0)] 
    supposing (ratreal(a) ≤ ratreal(b))
    ∧ (ratreal(f[a]) ≤ r0)
    ∧ (r0 ≤ ratreal(f[b]))
    ∧ (∀x,y:{x:ℝ| x ∈ [ratreal(a), ratreal(b)]} .  ((x = y) 
⇒ (g[x] = g[y])))
    ∧ (∀r:ℤ × ℕ+. ((ratreal(r) ∈ [ratreal(a), ratreal(b)]) 
⇒ (g[ratreal(r)] = ratreal(f[r]))))
Proof
Definitions occuring in Statement : 
ratreal: ratreal(r)
, 
rccint: [l, u]
, 
i-member: r ∈ I
, 
rleq: x ≤ y
, 
req: x = y
, 
int-to-real: r(n)
, 
real: ℝ
, 
nat_plus: ℕ+
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
sq_exists: ∃x:A [B[x]]
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
set: {x:A| B[x]} 
, 
function: x:A ⟶ B[x]
, 
product: x:A × B[x]
, 
natural_number: $n
, 
int: ℤ
Definitions unfolded in proof : 
member: t ∈ T
, 
so_apply: x[s]
, 
pi1: fst(t)
, 
so_lambda: λ2x.t[x]
, 
accelerate: accelerate(k;f)
, 
rational-fun-zero: rational-fun-zero(f;a;b)
, 
rational-IVT-1, 
common-limit-squeeze, 
rat-zero-cases, 
ravg-weak-between, 
ravg-dist-when-rleq, 
sq_stable__rleq, 
iff_weakening_uiff, 
rleq_functionality, 
req_functionality, 
rleq_weakening_equal, 
converges-to_functionality, 
const-rmul-limit-with-bound, 
rinv-exp-converges-ext, 
converges-iff-cauchy, 
sq-all-large-and, 
uall: ∀[x:A]. B[x]
, 
so_lambda: so_lambda(x,y,z,w.t[x; y; z; w])
, 
so_apply: x[s1;s2;s3;s4]
, 
so_lambda: λ2x y.t[x; y]
, 
top: Top
, 
so_apply: x[s1;s2]
, 
uimplies: b supposing a
Lemmas referenced : 
rational-IVT-1, 
lifting-strict-spread, 
istype-void, 
strict4-spread, 
lifting-strict-callbyvalue, 
lifting-strict-decide, 
strict4-decide, 
lifting-strict-less, 
common-limit-squeeze, 
rat-zero-cases, 
ravg-weak-between, 
ravg-dist-when-rleq, 
sq_stable__rleq, 
iff_weakening_uiff, 
rleq_functionality, 
req_functionality, 
rleq_weakening_equal, 
converges-to_functionality, 
const-rmul-limit-with-bound, 
rinv-exp-converges-ext, 
converges-iff-cauchy, 
sq-all-large-and
Rules used in proof : 
introduction, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
cut, 
instantiate, 
extract_by_obid, 
hypothesis, 
sqequalRule, 
thin, 
sqequalHypSubstitution, 
equalityTransitivity, 
equalitySymmetry, 
isectElimination, 
baseClosed, 
isect_memberEquality_alt, 
voidElimination, 
independent_isectElimination
Latex:
\mforall{}a,b:\mBbbZ{}  \mtimes{}  \mBbbN{}\msupplus{}.  \mforall{}f:(\mBbbZ{}  \mtimes{}  \mBbbN{}\msupplus{})  {}\mrightarrow{}  (\mBbbZ{}  \mtimes{}  \mBbbN{}\msupplus{}).
    \mforall{}[g:\{x:\mBbbR{}|  x  \mmember{}  [ratreal(a),  ratreal(b)]\}    {}\mrightarrow{}  \mBbbR{}]
        \mexists{}c:\{c:\mBbbR{}|  c  \mmember{}  [ratreal(a),  ratreal(b)]\}    [(g[c]  =  r0)] 
        supposing  (ratreal(a)  \mleq{}  ratreal(b))
        \mwedge{}  (ratreal(f[a])  \mleq{}  r0)
        \mwedge{}  (r0  \mleq{}  ratreal(f[b]))
        \mwedge{}  (\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  [ratreal(a),  ratreal(b)]\}  .    ((x  =  y)  {}\mRightarrow{}  (g[x]  =  g[y])))
        \mwedge{}  (\mforall{}r:\mBbbZ{}  \mtimes{}  \mBbbN{}\msupplus{}.  ((ratreal(r)  \mmember{}  [ratreal(a),  ratreal(b)])  {}\mRightarrow{}  (g[ratreal(r)]  =  ratreal(f[r]))))
Date html generated:
2019_10_30-AM-10_01_19
Last ObjectModification:
2019_04_02-AM-09_43_13
Theory : reals
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