Nuprl Lemma : geo-colinear-implies-between-or
∀e:EuclideanPlane. ∀a,b,c:Point.  (Colinear(a;b;c) ⇒ (¬¬((B(acb) ∨ B(bac)) ∨ B(abc))))
Proof
Definitions occuring in Statement : 
euclidean-plane: EuclideanPlane, 
geo-colinear: Colinear(a;b;c), 
geo-between: B(abc), 
geo-point: Point, 
all: ∀x:A. B[x], 
not: ¬A, 
implies: P ⇒ Q, 
or: P ∨ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
not: ¬A, 
false: False, 
geo-colinear: Colinear(a;b;c), 
geo-lsep: a # bc, 
and: P ∧ Q, 
cand: A c∧ B, 
or: P ∨ Q, 
member: t ∈ T, 
uall: ∀[x:A]. B[x], 
subtype_rel: A ⊆r B, 
prop: ℙ, 
oriented-plane: OrientedPlane, 
uimplies: b supposing a, 
guard: {T}
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c:Point.    (Colinear(a;b;c)  {}\mRightarrow{}  (\mneg{}\mneg{}((B(acb)  \mvee{}  B(bac))  \mvee{}  B(abc))))
Date html generated:
2020_05_20-AM-09_50_40
Last ObjectModification:
2019_12_23-AM-10_11_53
Theory : euclidean!plane!geometry
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