A program edit created new def-use associations that must be tested. For example consider the following code segment:
... 1. if (A > 1) then 2. Y=X+5; 3. else 4. Y=Y-5; 5. X=2; /* replace with X=2+Y */ ...If statement 5 is replaced with ``X=2+Y'', a new use of variable is introduced. Def-use association consisting of those definitions of Y that reach the new use of Y must be tested.