module Unit: Unittypet =unit=
| | | () | 
The unit type.
The constructor () is included here so that it has a path,
    but it is not intended to be used in user-defined data types.
val equal : t -> t -> boolequal u1 u2 is true.
val compare : t -> t -> intcompare u1 u2 is 0.
val to_string : t -> stringto_string b is "()".