Partial Ordering

partially ordered types.

Properties Let a be an instance of PartiallyOrdered, then holds:

1. For all x in a holds: x <<= x.
2. For all x, y in a holds: If x <<= y and y <<= x then x == y.
3. For all x, y, z in a holds: If x <<= y and y <<= z then x <<= z.

the minimal element of a patrially ordered type..

Property Let a be an instance of Empty, then for all x in a holds: empty <<= x.

the maximal element of a partially ordered type.

Property Let a be an instance of Full, then for all x in a holds: x <<= full.