Nuprl Lemma : rational-IVT-ext

∀a,b:ℝ. ∀f:(ℤ × ℕ+) ⟶ (ℤ × ℕ+).
  ∀[g:{x:ℝ| x ∈ [a, b]}  ⟶ ℝ]
    ∃c:{c:ℝ| c ∈ (a, b)}  [(g[c] = r0)] 
    supposing (a < b)
    ∧ ((g[a] * g[b]) < r0)
    ∧ (∀x,y:{x:ℝ| x ∈ [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: x = y,  rmul: a * b,  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],  subtract: n - 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 b then t else f 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: λ2x y.t[x; y],  top: Top,  so_apply: x[s1;s2],  uimplies: b 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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