Nuprl Lemma : rational-IVT-ext

a,b:ℝ. ∀f:(ℤ × ℕ+) ⟶ (ℤ × ℕ+).
  ∀[g:{x:ℝx ∈ [a, b]}  ⟶ ℝ]
    ∃c:{c:ℝc ∈ (a, b)}  [(g[c] r0)] 
    supposing (a < b)
    ∧ ((g[a] g[b]) < r0)
    ∧ (∀x,y:{x:ℝx ∈ [a, b]} .  ((x y)  (g[x] g[y])))
    ∧ (∀r:ℤ × ℕ+((ratreal(r) ∈ [a, b])  (g[ratreal(r)] ratreal(f[r]))))


Proof




Definitions occuring in Statement :  ratreal: ratreal(r) rooint: (l, u) rccint: [l, u] i-member: r ∈ I rless: x < y req: y rmul: b 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] subtract: m pi1: fst(t) ratreal: ratreal(r) rat-to-real: r(a/b) int-rdiv: (a)/k1 int-to-real: r(n) rlessw: rlessw(x;y) quick-find: quick-find(p;n) ifthenelse: if then else fi  int-rat-mul: int-rat-mul(n;x) so_lambda: λ2x.t[x] rational_fun_zero: rational_fun_zero(f;a;b) rational-IVT sq_stable__and sq_stable__rless rleq_functionality rat-zero-cases sq_stable__rleq 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 lifting-strict-callbyvalue istype-void strict4-spread lifting-strict-decide strict4-decide lifting-strict-spread lifting-strict-less sq_stable__and sq_stable__rless rleq_functionality rat-zero-cases sq_stable__rleq
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:\mBbbR{}.  \mforall{}f:(\mBbbZ{}  \mtimes{}  \mBbbN{}\msupplus{})  {}\mrightarrow{}  (\mBbbZ{}  \mtimes{}  \mBbbN{}\msupplus{}).
    \mforall{}[g:\{x:\mBbbR{}|  x  \mmember{}  [a,  b]\}    {}\mrightarrow{}  \mBbbR{}]
        \mexists{}c:\{c:\mBbbR{}|  c  \mmember{}  (a,  b)\}    [(g[c]  =  r0)] 
        supposing  (a  <  b)
        \mwedge{}  ((g[a]  *  g[b])  <  r0)
        \mwedge{}  (\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  [a,  b]\}  .    ((x  =  y)  {}\mRightarrow{}  (g[x]  =  g[y])))
        \mwedge{}  (\mforall{}r:\mBbbZ{}  \mtimes{}  \mBbbN{}\msupplus{}.  ((ratreal(r)  \mmember{}  [a,  b])  {}\mRightarrow{}  (g[ratreal(r)]  =  ratreal(f[r]))))



Date html generated: 2019_10_30-AM-10_05_07
Last ObjectModification: 2019_01_14-PM-00_30_53

Theory : reals


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