Nuprl Lemma : strict-increasing-implies-inv-strict-increasing

∀[I:Interval]. ∀[f:I ⟶ℝ].
  (∀x,y:{x:ℝ| x ∈ I} .  (((f x) < (f y)) ⇒ (x < y))) supposing 
     ((∀x,y:{x:ℝ| x ∈ I} .  ((x < y) ⇒ ((f x) < (f y)))) and 
     (∀x,y:{x:ℝ| x ∈ I} .  ((x = y) ⇒ ((f x) = (f y)))))


Proof




Definitions occuring in Statement :  rfun: I ⟶ℝ,  i-member: r ∈ I,  interval: Interval,  rless: x < y,  req: x = y,  real: ℝ,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  implies: P ⇒ Q,  set: {x:A| B[x]} ,  apply: f a
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  all: ∀x:A. B[x],  implies: P ⇒ Q,  rfun: I ⟶ℝ,  prop: ℙ,  sq_stable: SqStable(P),  squash: ↓T,  so_lambda: λ2x.t[x],  so_apply: x[s],  rneq: x ≠ y,  or: P ∨ Q,  guard: {T},  false: False
Lemmas referenced :  real-fun-implies-sfun-general,  req_witness,  i-member_wf,  req_wf,  real_wf,  sq_stable__rless,  rless_wf,  set_wf,  all_wf,  rfun_wf,  interval_wf,  rless_transitivity2,  rleq_weakening_rless,  rless_irreflexivity
Rules used in proof :  cut,  introduction,  extract_by_obid,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  hypothesis,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  sqequalRule,  lambdaEquality,  dependent_functionElimination,  applyEquality,  setElimination,  rename,  dependent_set_memberEquality,  because_Cache,  independent_functionElimination,  setEquality,  independent_isectElimination,  lambdaFormation,  imageMemberEquality,  baseClosed,  imageElimination,  functionEquality,  inlFormation,  unionElimination,  voidElimination

Latex:
\mforall{}[I:Interval].  \mforall{}[f:I  {}\mrightarrow{}\mBbbR{}].
    (\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  I\}  .    (((f  x)  <  (f  y))  {}\mRightarrow{}  (x  <  y)))  supposing 
          ((\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  I\}  .    ((x  <  y)  {}\mRightarrow{}  ((f  x)  <  (f  y))))  and 
          (\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  I\}  .    ((x  =  y)  {}\mRightarrow{}  ((f  x)  =  (f  y)))))



Date html generated: 2017_10_03-AM-09_57_15
Last ObjectModification: 2017_08_31-PM-01_21_40

Theory : reals


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