Nuprl Lemma : i-member-convex

∀I:Interval. ∀a,b:ℝ.  ((a ∈ I) ⇒ (b ∈ I) ⇒ (∀t:ℝ. ((r0 ≤ t) ⇒ (t ≤ r1) ⇒ ((t * a) + ((r1 - t) * b) ∈ I))))


Proof




Definitions occuring in Statement :  i-member: r ∈ I,  interval: Interval,  rleq: x ≤ y,  rsub: x - y,  rmul: a * b,  radd: a + b,  int-to-real: r(n),  real: ℝ,  all: ∀x:A. B[x],  implies: P ⇒ Q,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x],  prop: ℙ
Lemmas referenced :  i-member-between,  rmin_wf,  rmax_wf,  rmin-i-member,  rmax-i-member,  radd_wf,  rmul_wf,  rsub_wf,  int-to-real_wf,  rmin-lb-convex,  rmax-ub-convex,  rleq_wf,  real_wf,  i-member_wf,  interval_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  isectElimination,  hypothesis,  independent_functionElimination,  natural_numberEquality

Latex:
\mforall{}I:Interval.  \mforall{}a,b:\mBbbR{}.
    ((a  \mmember{}  I)  {}\mRightarrow{}  (b  \mmember{}  I)  {}\mRightarrow{}  (\mforall{}t:\mBbbR{}.  ((r0  \mleq{}  t)  {}\mRightarrow{}  (t  \mleq{}  r1)  {}\mRightarrow{}  ((t  *  a)  +  ((r1  -  t)  *  b)  \mmember{}  I))))



Date html generated: 2018_05_22-PM-02_05_36
Last ObjectModification: 2017_10_20-PM-04_50_38

Theory : reals


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