Nuprl Lemma : IVT-strictly-increasing-open

∀a:ℝ. ∀b:{b:ℝ| a < b} . ∀f:[a, b] ⟶ℝ.
  f[x] strictly-increasing for x ∈ (a, b) ⇒ (∀c:ℝ. ((f(a) < c) ⇒ (c < f(b)) ⇒ (∃x:ℝ. ((x ∈ (a, b)) ∧ (f(x) = c))))) 
  supposing ∀x,y:{x:ℝ| x ∈ [a, b]} .  ((x = y) ⇒ (f[x] = f[y]))


Proof




Definitions occuring in Statement :  strictly-increasing-on-interval: f[x] strictly-increasing for x ∈ I,  r-ap: f(x),  rfun: I ⟶ℝ,  rooint: (l, u),  rccint: [l, u],  i-member: r ∈ I,  rless: x < y,  req: x = y,  real: ℝ,  uimplies: b supposing a,  so_apply: x[s],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q,  set: {x:A| B[x]} 
Definitions unfolded in proof :  all: ∀x:A. B[x],  member: t ∈ T,  uimplies: b supposing a,  implies: P ⇒ Q,  uall: ∀[x:A]. B[x],  so_apply: x[s],  rfun: I ⟶ℝ,  subinterval: I ⊆ J ,  top: Top,  and: P ∧ Q,  cand: A c∧ B,  guard: {T},  prop: ℙ,  so_lambda: λ2x.t[x],  label: ...$L... t,  subtype_rel: A ⊆r B,  i-member: r ∈ I,  rccint: [l, u],  rooint: (l, u),  locally-non-constant: locally-non-constant(f;a;b;c),  strictly-increasing-on-interval: f[x] strictly-increasing for x ∈ I,  or: P ∨ Q,  exists: ∃x:A. B[x],  rneq: x ≠ y,  r-ap: f(x)
Lemmas referenced :  IVT-locally-non-constant-open,  req_witness,  member_rooint_lemma,  istype-void,  member_rccint_lemma,  rleq_weakening_rless,  rless_wf,  strictly-increasing-on-interval_wf,  rooint_wf,  subtype_rel_sets_simple,  real_wf,  i-member_wf,  rccint_wf,  req_wf,  rfun_wf,  rless_transitivity1,  rless_transitivity2,  rleq_wf,  rless-cases,  rleq_weakening_equal,  r-ap_wf,  rleq_transitivity,  rneq_wf
Rules used in proof :  cut,  introduction,  extract_by_obid,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  hypothesis,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  isect_memberFormation_alt,  sqequalRule,  lambdaEquality_alt,  isectElimination,  applyEquality,  because_Cache,  independent_functionElimination,  functionIsTypeImplies,  inhabitedIsType,  rename,  independent_isectElimination,  isect_memberEquality_alt,  voidElimination,  productElimination,  independent_pairFormation,  setElimination,  productIsType,  universeIsType,  setIsType,  functionIsType,  dependent_set_memberEquality_alt,  unionElimination,  dependent_pairFormation_alt,  inlFormation_alt,  inrFormation_alt

Latex:
\mforall{}a:\mBbbR{}.  \mforall{}b:\{b:\mBbbR{}|  a  <  b\}  .  \mforall{}f:[a,  b]  {}\mrightarrow{}\mBbbR{}.
    f[x]  strictly-increasing  for  x  \mmember{}  (a,  b)
    {}\mRightarrow{}  (\mforall{}c:\mBbbR{}.  ((f(a)  <  c)  {}\mRightarrow{}  (c  <  f(b))  {}\mRightarrow{}  (\mexists{}x:\mBbbR{}.  ((x  \mmember{}  (a,  b))  \mwedge{}  (f(x)  =  c))))) 
    supposing  \mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  [a,  b]\}  .    ((x  =  y)  {}\mRightarrow{}  (f[x]  =  f[y]))



Date html generated: 2019_10_30-AM-09_09_49
Last ObjectModification: 2019_04_02-PM-00_03_33

Theory : reals


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