Provides a variable translation over an invariant at one program
point (perhaps in a different program) to a similar invariant at a
second program point. In general, on order for a translation to be
possible, the invariants must be of the same class. For example,
consider the invariants (x>y) at ppt1 and (p>q) at ppt2. Since the
invariants are the same, the translation is (x -> p) and (y -> q)
The quality of the translation is also determined (approximately on
a scale of 0 to 100). If the invariants are not of the same class,
no translation is possible and the quality is zero. If the class
and the formula are the same, the match is excellent (80). If the
class is the same and the formula is different, the match is mediocre (40).
The quality is increased for variables with exactly the same derivation
and decreased for those with different derivations.
Other checks could be added to further specify the quality. For example,
if one invariant is a precondition and the other is a postcondition,
the quality should be reduced.