Nuprl Lemma : IVT-from-connected

∀u,v:ℝ. ∀f:[u, v] ⟶ℝ.
  ((u ≤ v)
  ⇒ (∀x,y:{x:ℝ| x ∈ [u, v]} .  ((x = y) ⇒ (f(x) = f(y))))
  ⇒ (f(u) < r0)
  ⇒ (r0 < f(v))
  ⇒ (∀e:{e:ℝ| r0 < e} . ∃c:{c:ℝ| c ∈ [u, v]} . (|f(c)| < e)))


Proof




Definitions occuring in Statement :  r-ap: f(x),  rfun: I ⟶ℝ,  rccint: [l, u],  i-member: r ∈ I,  rleq: x ≤ y,  rless: x < y,  rabs: |x|,  req: x = y,  int-to-real: r(n),  real: ℝ,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q,  set: {x:A| B[x]} ,  natural_number: $n
Definitions unfolded in proof :  iff: P ⇐⇒ Q,  or: P ∨ Q,  not: ¬A,  false: False,  req_int_terms: t1 ≡ t2,  rgt: x > y,  rge: x ≥ y,  rev_implies: P ⇐ Q,  uiff: uiff(P;Q),  cand: A c∧ B,  exists: ∃x:A. B[x],  guard: {T},  squash: ↓T,  sq_stable: SqStable(P),  top: Top,  and: P ∧ Q,  rccint: [l, u],  i-member: r ∈ I,  so_apply: x[s],  uimplies: b supposing a,  prop: ℙ,  so_lambda: λ2x.t[x],  uall: ∀[x:A]. B[x],  connected: Connected(X),  implies: P ⇒ Q,  member: t ∈ T,  all: ∀x:A. B[x]
Lemmas referenced :  rabs_wf,  rabs-rless-iff,  rless-cases,  real_term_value_minus_lemma,  real_term_value_const_lemma,  real_term_value_var_lemma,  real_term_value_sub_lemma,  real_polynomial_null,  rless_functionality_wrt_implies,  req-iff-rsub-is-0,  itermMinus_wf,  itermConstant_wf,  itermVar_wf,  itermSubtract_wf,  rsub_wf,  rless-implies-rless,  rleq_weakening_rless,  rfun_wf,  rleq_wf,  req_wf,  all_wf,  rleq_weakening_equal,  int-to-real_wf,  set_wf,  rless_transitivity1,  req_inversion,  sq_stable__i-member,  rleq_weakening,  rless_transitivity2,  sq_stable__rleq,  member_rccint_lemma,  sq_stable__rless,  rminus_wf,  r-ap_wf,  rless_wf,  real_wf,  rccint_wf,  i-member_wf,  closed-interval-connected
Rules used in proof :  inlFormation,  inrFormation,  unionElimination,  intEquality,  int_eqEquality,  approximateComputation,  productEquality,  dependent_set_memberEquality,  dependent_pairFormation,  functionEquality,  natural_numberEquality,  imageElimination,  baseClosed,  imageMemberEquality,  productElimination,  voidEquality,  voidElimination,  isect_memberEquality,  independent_pairFormation,  independent_functionElimination,  because_Cache,  setEquality,  independent_isectElimination,  rename,  setElimination,  lambdaEquality,  sqequalRule,  isectElimination,  hypothesisEquality,  thin,  dependent_functionElimination,  sqequalHypSubstitution,  hypothesis,  lambdaFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution,  extract_by_obid,  introduction,  cut

Latex:
\mforall{}u,v:\mBbbR{}.  \mforall{}f:[u,  v]  {}\mrightarrow{}\mBbbR{}.
    ((u  \mleq{}  v)
    {}\mRightarrow{}  (\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  [u,  v]\}  .    ((x  =  y)  {}\mRightarrow{}  (f(x)  =  f(y))))
    {}\mRightarrow{}  (f(u)  <  r0)
    {}\mRightarrow{}  (r0  <  f(v))
    {}\mRightarrow{}  (\mforall{}e:\{e:\mBbbR{}|  r0  <  e\}  .  \mexists{}c:\{c:\mBbbR{}|  c  \mmember{}  [u,  v]\}  .  (|f(c)|  <  e)))



Date html generated: 2018_05_22-PM-02_16_48
Last ObjectModification: 2018_05_21-AM-00_31_50

Theory : reals


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