Patching Programs
Eval points let you patch your programs and route around code that you want replaced, supporting:
*Branching around code that you don’t want your program to execute.
*Adding new statements.
In many cases, correcting an error means that you will do both operations: use a goto to branch around incorrect lines and add corrections.
For example, suppose you need to change several statements. Just add these to an action point, then add a goto (C) or GOTO (Fortran) statement that jumps over the code you no longer want executed. For example, the eval point in Figure 110 executes three statements and then skips to line 656.
 
Figure 110, Patching Using an Eval Point