Nuprl Lemma : rational-IVT-2

a,b:ℤ × ℕ+. ∀f:(ℤ × ℕ+) ⟶ (ℤ × ℕ+).
  ∀[g:{x:ℝx ∈ [ratreal(a), ratreal(b)]}  ⟶ ℝ]
    ∃c:{c:ℝc ∈ [ratreal(a), ratreal(b)]}  [(g[c] r0)] 
    supposing (ratreal(a) ≤ ratreal(b))
    ∧ (ratreal(f[a]) ≤ r0)
    ∧ (r0 ≤ ratreal(f[b]))
    ∧ (∀x,y:{x:ℝx ∈ [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: y int-to-real: r(n) real: nat_plus: + uimplies: supposing a uall: [x:A]. B[x] so_apply: x[s] all: x:A. B[x] sq_exists: x:A [B[x]] implies:  Q and: P ∧ Q set: {x:A| B[x]}  function: x:A ⟶ B[x] product: x:A × B[x] natural_number: $n int:
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: λ2y.t[x; y] top: Top so_apply: x[s1;s2] uimplies: 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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