element added. Given a domain D, the lifted domain, lift D
contains an element lift d corresponding to each element d in
D with the same ordering as in D and a new element bottom
which is less than every other element in lift D.
data LiftedInt = K Int
contains the values K minint .. K maxint and K bottom,
corresponding to the values in Int, and a new value bottom.
This denotes the fact that when computing a value v = (K n)
the computation of either n or v may fail to terminate
yielding the values (K bottom) or bottom respectively.
(In LaTeX, a lifted domain or element is indicated by a