The Rectangle structure contains functions to compute with rectangles.
structure Rectangle : sig type POINT = { x: int, y: int } type RECT = { top: int, left: int, bottom: int, right: int } val EqualRect : RECT * RECT -> bool val InflateRect : RECT * int * int -> unit * RECT val IntersectRect : RECT * RECT -> bool * RECT val IsRectEmpty : RECT -> bool val OffsetRect : RECT * int * int -> RECT val PtInRect : RECT * POINT -> bool val SetRect : int * int * int * int -> RECT val SetRectEmpty : unit -> RECT val SubtractRect : RECT * RECT -> RECT val UnionRect : RECT * RECT -> RECT end