module Point:sig..end
typet =float * float
typepoint =t
val proj : 'a * 'b -> 'a
val proj' : 'a * 'b -> 'b
val middle : float * float -> float * float -> float * float
val distance : float * float -> float * float -> float
val (+) : float * float -> float * float -> float * float
val (-) : float * float -> float * float -> float * float
val (/) : float * float -> float -> float * float