Nuprl Lemma : rv-pos-angle-implies

∀n:ℕ. ∀a,b,c:ℝ^n.
  (rv-pos-angle(n;a;b;c)
  ⇒ (rv-pos-angle(n;c;b;a)
     ∧ rv-pos-angle(n;c;a;b)
     ∧ a ≠ c
     ∧ (¬a-b-c)
     ∧ (∀z:ℝ^n. (z ≠ b ⇒ (¬rv-pos-angle(n;a;b;z)) ⇒ rv-pos-angle(n;z;b;c)))))


Proof




Definitions occuring in Statement :  rv-between: a-b-c,  real-vec-sep: a ≠ b,  rv-pos-angle: rv-pos-angle(n;a;b;c),  real-vec: ℝ^n,  nat: ℕ,  all: ∀x:A. B[x],  not: ¬A,  implies: P ⇒ Q,  and: P ∧ Q
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q,  cand: A c∧ B,  member: t ∈ T,  uall: ∀[x:A]. B[x],  uimplies: b supposing a,  prop: ℙ
Lemmas referenced :  rv-pos-angle-symmetry,  rv-pos-angle-permute,  rv-pos-angle-implies-separated,  rv-pos-angle-not-between,  rv-pos-angle-shift,  not_wf,  rv-pos-angle_wf,  real-vec-sep_wf,  real-vec_wf,  nat_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  independent_functionElimination,  hypothesis,  independent_pairFormation,  because_Cache,  isectElimination,  independent_isectElimination

Latex:
\mforall{}n:\mBbbN{}.  \mforall{}a,b,c:\mBbbR{}\^{}n.
    (rv-pos-angle(n;a;b;c)
    {}\mRightarrow{}  (rv-pos-angle(n;c;b;a)
          \mwedge{}  rv-pos-angle(n;c;a;b)
          \mwedge{}  a  \mneq{}  c
          \mwedge{}  (\mneg{}a-b-c)
          \mwedge{}  (\mforall{}z:\mBbbR{}\^{}n.  (z  \mneq{}  b  {}\mRightarrow{}  (\mneg{}rv-pos-angle(n;a;b;z))  {}\mRightarrow{}  rv-pos-angle(n;z;b;c)))))



Date html generated: 2017_10_03-AM-11_07_17
Last ObjectModification: 2017_03_02-PM-05_32_36

Theory : reals


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