Nuprl Lemma : real-path-comp-exists

f,g:[r0, r1] ⟶ℝ.
  ((∀x,y:{x:ℝx ∈ [r0, r1]} .  ((x y)  (f(x) f(y))))
   (∀x,y:{x:ℝx ∈ [r0, r1]} .  ((x y)  (g(x) g(y))))
   (f(r1) g(r0))
   (∃h:[r0, r1] ⟶ℝ
       ((∀t:{x:ℝx ∈ [r0, (r1/r(2))]} (h(t) f(r(2) t)))
       ∧ (∀t:{x:ℝx ∈ [(r1/r(2)), r1]} (h(t) g((r(2) t) r1)))
       ∧ (∀x,y:{x:ℝx ∈ [r0, r1]} .  ((x y)  (h(x) h(y)))))))


Proof




Definitions occuring in Statement :  r-ap: f(x) rfun: I ⟶ℝ rccint: [l, u] i-member: r ∈ I rdiv: (x/y) rsub: y req: y rmul: b int-to-real: r(n) real: all: x:A. B[x] exists: x:A. B[x] implies:  Q and: P ∧ Q set: {x:A| B[x]}  natural_number: $n
Definitions unfolded in proof :  rev_uimplies: rev_uimplies(P;Q) req_int_terms: t1 ≡ t2 rdiv: (x/y) rccint: [l, u] i-member: r ∈ I uiff: uiff(P;Q) exists: x:A. B[x] satisfiable_int_formula: satisfiable_int_formula(fmla) decidable: Dec(P) nat_plus: + not: ¬A false: False le: A ≤ B cand: c∧ B sq_stable: SqStable(P) prop: true: True less_than': less_than'(a;b) squash: T less_than: a < b rev_implies:  Q and: P ∧ Q iff: ⇐⇒ Q or: P ∨ Q guard: {T} rneq: x ≠ y uimplies: supposing a member: t ∈ T uall: [x:A]. B[x] implies:  Q all: x:A. B[x] r-ap: f(x) so_apply: x[s] sq_exists: x:A [B[x]] rless: x < y rfun: I ⟶ℝ rtermSubtract: left "-" right pi2: snd(t) rtermDivide: num "/" denom rtermMultiply: left "*" right pi1: fst(t) rat_term_ind: rat_term_ind rtermConstant: "const" rat_term_to_real: rat_term_to_real(f;t) so_lambda: λ2x.t[x] subtype_rel: A ⊆B cauchy: cauchy(n.x[n]) ge: i ≥  nat: real: absval: |i| rge: x ≥ y converges-to: lim n→∞.x[n] y rleq: x ≤ y rnonneg: rnonneg(x)

Latex:
\mforall{}f,g:[r0,  r1]  {}\mrightarrow{}\mBbbR{}.
    ((\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  [r0,  r1]\}  .    ((x  =  y)  {}\mRightarrow{}  (f(x)  =  f(y))))
    {}\mRightarrow{}  (\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  [r0,  r1]\}  .    ((x  =  y)  {}\mRightarrow{}  (g(x)  =  g(y))))
    {}\mRightarrow{}  (f(r1)  =  g(r0))
    {}\mRightarrow{}  (\mexists{}h:[r0,  r1]  {}\mrightarrow{}\mBbbR{}
              ((\mforall{}t:\{x:\mBbbR{}|  x  \mmember{}  [r0,  (r1/r(2))]\}  .  (h(t)  =  f(r(2)  *  t)))
              \mwedge{}  (\mforall{}t:\{x:\mBbbR{}|  x  \mmember{}  [(r1/r(2)),  r1]\}  .  (h(t)  =  g((r(2)  *  t)  -  r1)))
              \mwedge{}  (\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  [r0,  r1]\}  .    ((x  =  y)  {}\mRightarrow{}  (h(x)  =  h(y)))))))



Date html generated: 2020_05_20-PM-00_13_36
Last ObjectModification: 2020_01_08-AM-01_01_39

Theory : reals


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