Nuprl Lemma : strictly-increasing-on-closed-interval2

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


Proof




Definitions occuring in Statement :  strictly-increasing-on-interval: f[x] strictly-increasing for x ∈ I,  rfun: I ⟶ℝ,  rooint: (l, u),  rccint: [l, u],  i-member: r ∈ I,  rleq: x ≤ y,  req: x = y,  real: ℝ,  so_apply: x[s],  all: ∀x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q,  set: {x:A| B[x]} 
Definitions unfolded in proof :  subtype_rel: A ⊆r B,  label: ...$L... t,  rfun: I ⟶ℝ,  so_apply: x[s],  so_lambda: λ2x.t[x],  prop: ℙ,  uimplies: b supposing a,  guard: {T},  uall: ∀[x:A]. B[x],  cand: A c∧ B,  and: P ∧ Q,  implies: P ⇒ Q,  top: Top,  subinterval: I ⊆ J ,  member: t ∈ T,  all: ∀x:A. B[x],  increasing-on-interval: f[x] increasing for x ∈ I,  false: False,  or: P ∨ Q,  not: ¬A,  stable: Stable{P},  strictly-increasing-on-interval: f[x] strictly-increasing for x ∈ I,  squash: ↓T,  sq_stable: SqStable(P)
Lemmas referenced :  rfun_wf,  req_wf,  subtype_rel_sets,  rooint_wf,  strictly-increasing-on-interval_wf,  rleq_transitivity,  rleq_weakening_equal,  rleq_wf,  rccint_wf,  i-member_wf,  all_wf,  real_wf,  rless_wf,  rleq_weakening_rless,  member_rccint_lemma,  member_rooint_lemma,  strictly-increasing-on-closed-interval,  set_wf,  minimal-not-not-excluded-middle,  minimal-double-negation-hyp-elim,  not_wf,  or_wf,  false_wf,  stable__rleq,  rless_transitivity2,  rless_transitivity1,  rleq_weakening,  rleq_antisymmetry,  not-rless,  req_inversion,  sq_stable__rleq
Rules used in proof :  functionEquality,  dependent_set_memberEquality,  because_Cache,  applyEquality,  rename,  setElimination,  lambdaEquality,  setEquality,  independent_functionElimination,  productEquality,  independent_pairFormation,  independent_isectElimination,  isectElimination,  productElimination,  voidEquality,  voidElimination,  isect_memberEquality,  sqequalRule,  hypothesisEquality,  thin,  dependent_functionElimination,  sqequalHypSubstitution,  hypothesis,  lambdaFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution,  extract_by_obid,  introduction,  cut,  unionElimination,  imageElimination,  baseClosed,  imageMemberEquality

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



Date html generated: 2017_10_03-PM-00_29_43
Last ObjectModification: 2017_07_30-PM-08_56_24

Theory : reals


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