След на паутине

import Data.List
import Data.Maybe

data Entity a = Entity { circle :: Circle a}
data Position a = Position {x, y :: a} 
data Circle a = Circle {position :: (Position a), r :: a} 

entityIntersect (Circle p1 r1) (Entity(Circle p2 r2)) =
   sqr (r1 + r2) < sqr (x p1 - x p2) + sqr (y p1 - y p2)
   where sqr = (^2)

findIntersecting x entities =
   find (entityIntersect x) entities