Nuprl Lemma : near-inverse-of-increasing-function-ext

∀f:ℝ ⟶ ℝ. ∀n,M:ℕ+. ∀z:ℝ. ∀a,b:ℤ.
  ∀k:ℕ+
    (∃c:ℤ. (∃j:ℕ+ [((|f[(r(c))/j] - z| ≤ (r1/r(n))) ∧ ((r(a))/k ≤ (r(c))/j) ∧ ((r(c))/j ≤ (r(b))/k))])) supposing 
       ((z ≤ f[(r(b))/k]) and 
       (f[(r(a))/k] ≤ z) and 
       (∀x,y:ℝ.
          (((r(a))/k ≤ x)
          ⇒ (x < y)
          ⇒ (y ≤ (r(b))/k)
          ⇒ ((f[x] ≤ f[y]) ∧ (((y - x) ≤ (r1/r(M))) ⇒ ((f[y] - f[x]) ≤ (r1/r(n)))))))) 
  supposing a < b


Proof




Definitions occuring in Statement :  rdiv: (x/y),  rleq: x ≤ y,  rless: x < y,  rabs: |x|,  int-rdiv: (a)/k1,  rsub: x - y,  int-to-real: r(n),  real: ℝ,  nat_plus: ℕ+,  less_than: a < b,  uimplies: b supposing a,  so_apply: x[s],  all: ∀x:A. B[x],  sq_exists: ∃x:A [B[x]],  exists: ∃x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q,  function: x:A ⟶ B[x],  natural_number: $n,  int: ℤ
Definitions unfolded in proof :  member: t ∈ T,  subtract: n - m,  so_apply: x[s],  genrec-ap: genrec-ap,  near-inverse-of-increasing-function,  decidable__le,  uniform-comp-nat-induction,  nearby-cases,  decidable__and,  decidable__not,  decidable__less_than',  decidable__lt,  rleq_functionality_wrt_implies,  decidable__implies,  decidable__false,  any: any x,  decidable__squash,  decidable_functionality,  squash_elim,  sq_stable_from_decidable,  iff_preserves_decidability,  sq_stable__from_stable,  stable__from_decidable,  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.t[x],  top: Top,  uimplies: b supposing a
Lemmas referenced :  near-inverse-of-increasing-function,  lifting-strict-decide,  istype-void,  strict4-decide,  lifting-strict-less,  lifting-strict-callbyvalue,  decidable__le,  uniform-comp-nat-induction,  nearby-cases,  decidable__and,  decidable__not,  decidable__less_than',  decidable__lt,  rleq_functionality_wrt_implies,  decidable__implies,  decidable__false,  decidable__squash,  decidable_functionality,  squash_elim,  sq_stable_from_decidable,  iff_preserves_decidability,  sq_stable__from_stable,  stable__from_decidable
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{}f:\mBbbR{}  {}\mrightarrow{}  \mBbbR{}.  \mforall{}n,M:\mBbbN{}\msupplus{}.  \mforall{}z:\mBbbR{}.  \mforall{}a,b:\mBbbZ{}.
    \mforall{}k:\mBbbN{}\msupplus{}
        (\mexists{}c:\mBbbZ{}
            (\mexists{}j:\mBbbN{}\msupplus{}  [((|f[(r(c))/j]  -  z|  \mleq{}  (r1/r(n)))
                          \mwedge{}  ((r(a))/k  \mleq{}  (r(c))/j)
                          \mwedge{}  ((r(c))/j  \mleq{}  (r(b))/k))]))  supposing 
              ((z  \mleq{}  f[(r(b))/k])  and 
              (f[(r(a))/k]  \mleq{}  z)  and 
              (\mforall{}x,y:\mBbbR{}.
                    (((r(a))/k  \mleq{}  x)
                    {}\mRightarrow{}  (x  <  y)
                    {}\mRightarrow{}  (y  \mleq{}  (r(b))/k)
                    {}\mRightarrow{}  ((f[x]  \mleq{}  f[y])  \mwedge{}  (((y  -  x)  \mleq{}  (r1/r(M)))  {}\mRightarrow{}  ((f[y]  -  f[x])  \mleq{}  (r1/r(n)))))))) 
    supposing  a  <  b



Date html generated: 2019_10_29-AM-10_07_00
Last ObjectModification: 2019_02_05-PM-04_47_42

Theory : reals


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