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fom
Posts:
1,968
Registered:
12/4/12


Re: Collinear
Posted:
May 7, 2013 6:25 PM


On 5/7/2013 2:48 AM, William Elliot wrote: > Let C be a collection of n points with the property that > any line L with two points of C on it, has a third point > of C on it. > > How is it that C is collinear, ie all points of C are > on a single line? >
Is this true?
If I recall, there is something from design theory called a Pasch configuration.
ABC AEF BDF CDE
C  B   D  AEF
Maybe I am not recalling correctly.
This is better:
http://mathworld.wolfram.com/PaschConfiguration.html



