Nuprl Lemma : geo-colinear-left-out3
∀e:EuclideanPlane. ∀a,b,c,a',c',x,x':Point.
  (Colinear(b;x;x') 
⇒ a-x-c 
⇒ a'-x'-c' 
⇒ out(b aa') 
⇒ out(b cc') 
⇒ b leftof ac 
⇒ b leftof a'c' 
⇒ out(b xx'))
Proof
Definitions occuring in Statement : 
geo-out: out(p ab)
, 
euclidean-plane: EuclideanPlane
, 
geo-colinear: Colinear(a;b;c)
, 
geo-strict-between: a-b-c
, 
geo-left: a leftof bc
, 
geo-point: Point
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
guard: {T}
, 
uimplies: b supposing a
, 
basic-geometry-: BasicGeometry-
, 
geo-out: out(p ab)
, 
and: P ∧ Q
, 
cand: A c∧ B
, 
not: ¬A
, 
geo-eq: a ≡ b
, 
prop: ℙ
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
false: False
, 
basic-geometry: BasicGeometry
, 
geo-strict-between: a-b-c
, 
geo-sep: a # b
, 
subtract: n - m
, 
cons: [a / b]
, 
select: L[n]
, 
true: True
, 
squash: ↓T
, 
less_than: a < b
, 
less_than': less_than'(a;b)
, 
le: A ≤ B
, 
lelt: i ≤ j < k
, 
int_seg: {i..j-}
, 
top: Top
, 
l_all: (∀x∈L.P[x])
, 
geo-colinear-set: geo-colinear-set(e; L)
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c,a',c',x,x':Point.
    (Colinear(b;x;x')
    {}\mRightarrow{}  a-x-c
    {}\mRightarrow{}  a'-x'-c'
    {}\mRightarrow{}  out(b  aa')
    {}\mRightarrow{}  out(b  cc')
    {}\mRightarrow{}  b  leftof  ac
    {}\mRightarrow{}  b  leftof  a'c'
    {}\mRightarrow{}  out(b  xx'))
Date html generated:
2020_05_20-AM-09_59_23
Last ObjectModification:
2020_01_13-PM-03_43_57
Theory : euclidean!plane!geometry
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