Class for partially ordered data types. Instances should satisfy the following laws for all values a, b and c:
But note that the floating point instances don't satisfy the first rule.
Minimal definition: posetCmp or leq.
Is comparable to.
Is not comparable to.
Less than or equal.
Greater than or equal.
Strict less than.
Strict greater than.
Are two elements of the underlying comparabale or not; if they are, then Ordering tell the relation between them.