Nuprl Lemma : rational_fun_zero_wf

∀a,b:ℝ. ∀f:(ℤ × ℕ+) ⟶ (ℤ × ℕ+).
  ∀[g:{x:ℝ| x ∈ [a, b]}  ⟶ ℝ]
    rational_fun_zero(f;a;b) ∈ {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 :  rational_fun_zero: rational_fun_zero(f;a;b),  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],  implies: P ⇒ Q,  and: P ∧ Q,  member: t ∈ T,  set: {x:A| B[x]} ,  function: x:A ⟶ B[x],  product: x:A × B[x],  natural_number: $n,  int: ℤ
Definitions unfolded in proof :  all: ∀x:A. B[x],  uall: ∀[x:A]. B[x],  uimplies: b supposing a,  member: t ∈ T,  rational-IVT-ext,  rational_fun_zero: rational_fun_zero(f;a;b),  mu-ge: mu-ge(f;n),  ifthenelse: if b then t else f fi ,  band: p ∧b q,  le_int: i ≤z j,  bnot: ¬bb,  lt_int: i <z j,  and: P ∧ Q,  top: Top,  so_apply: x[s],  sq_exists: ∃x:A [B[x]],  implies: P ⇒ Q,  subtype_rel: A ⊆r B,  i-member: r ∈ I,  rccint: [l, u],  rooint: (l, u),  so_lambda: λ2x.t[x],  prop: ℙ,  cand: A c∧ B,  guard: {T},  sq_stable: SqStable(P),  squash: ↓T
Lemmas referenced :  rational-IVT-ext,  member_rccint_lemma,  istype-void,  member_rooint_lemma,  real_wf,  subtype_rel_self,  all_wf,  uall_wf,  rleq_wf,  isect_wf,  rless_wf,  rmul_wf,  rleq_weakening_equal,  rleq_weakening_rless,  int-to-real_wf,  req_wf,  nat_plus_wf,  ratreal_wf,  sq_exists_wf,  subtype_rel_sets,  subtype_rel_sets_simple,  i-member_wf,  rccint_wf,  sq_stable__rless,  istype-int
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  isect_memberFormation_alt,  cut,  thin,  instantiate,  extract_by_obid,  hypothesis,  sqequalRule,  sqequalHypSubstitution,  productElimination,  applyEquality,  introduction,  dependent_functionElimination,  isect_memberEquality_alt,  voidElimination,  functionExtensionality,  hypothesisEquality,  because_Cache,  isectElimination,  functionEquality,  lambdaEquality_alt,  setEquality,  productEquality,  inhabitedIsType,  setElimination,  rename,  independent_isectElimination,  independent_pairFormation,  dependent_set_memberEquality_alt,  productIsType,  universeIsType,  closedConclusion,  natural_numberEquality,  setIsType,  intEquality,  functionIsType,  equalityTransitivity,  equalitySymmetry,  independent_functionElimination,  imageMemberEquality,  baseClosed,  imageElimination,  equalityIstype

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{}]
        rational\_fun\_zero(f;a;b)  \mmember{}  \{c:\mBbbR{}|  (c  \mmember{}  (a,  b))  \mwedge{}  (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_39
Last ObjectModification: 2019_01_14-PM-00_34_14

Theory : reals


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