Nuprl Lemma : ip-triangle-implies
∀rv:InnerProductSpace. ∀a,b,c:Point.
  (Δ(a;b;c) 
⇒ (Δ(c;b;a) ∧ Δ(c;a;b) ∧ a # c ∧ (¬a_b_c) ∧ (∀z:Point. (z # b 
⇒ (¬Δ(a;b;z)) 
⇒ Δ(z;b;c)))))
Proof
Definitions occuring in Statement : 
ip-triangle: Δ(a;b;c)
, 
ip-between: a_b_c
, 
inner-product-space: InnerProductSpace
, 
ss-sep: x # y
, 
ss-point: Point
, 
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
, 
subtype_rel: A ⊆r B
Lemmas referenced : 
ip-triangle-symmetry, 
ip-triangle-permute, 
ip-triangle-implies-separated, 
ip-triangle-not-between, 
ip-triangle-shift, 
not_wf, 
ip-triangle_wf, 
ss-sep_wf, 
ss-point_wf, 
inner-product-space_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, 
isectElimination, 
independent_isectElimination, 
because_Cache, 
applyEquality, 
sqequalRule
Latex:
\mforall{}rv:InnerProductSpace.  \mforall{}a,b,c:Point.
    (\mDelta{}(a;b;c)
    {}\mRightarrow{}  (\mDelta{}(c;b;a)  \mwedge{}  \mDelta{}(c;a;b)  \mwedge{}  a  \#  c  \mwedge{}  (\mneg{}a\_b\_c)  \mwedge{}  (\mforall{}z:Point.  (z  \#  b  {}\mRightarrow{}  (\mneg{}\mDelta{}(a;b;z))  {}\mRightarrow{}  \mDelta{}(z;b;c)))))
Date html generated:
2017_10_04-PM-11_59_06
Last ObjectModification:
2017_08_10-PM-03_38_19
Theory : inner!product!spaces
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