type point
= int * int
val ccw : point -> point -> point -> bool
The counterclockwise relation ccw p q r
states that the circle through points (p,q,r)
is traversed counterclockwise when we encounter the points in cyclic order p,q,r,p,...
*
val in_circle : point -> point -> point -> point -> bool
The relation in_circle p q r s
states that s
lies inside the circle (p,q,r)
if ccw p q r
is true, or outside that circle if ccw p q r
is false.