A type formed by applying Some type conStructor function to one or more other typeS. The uSual conStructionS are functionS: t1 -> t2, productS: (t1, t2), SumS: t1 + t2 and lifting: lift(t1). (In LaTeX, the lifted type iS written with a SubScript perp). See alSo algebraic data type, primitive type. (1995-02-03)