1. A method of creating constraints for use with object code insertion technology, said method comprising: deriving an A-representation and a B-representation for values produced by execution of instructions of a portion of object code, wherein prior to object code insertion the A-representation and the B-representation of a value produced by a same instruction are equivalent; identifying equalities between A-representations of values produced by different instructions; and determining constraints from the identified equalities using B-representations, where the constraints are observed after object code insertion.