EDB/fact selection

[rainLiuplus]

The following questions pertain to choosing the appropriate EDBs and facts to repair programs.

1. What is the method for selecting the EDBs that will be symbolized to generate target tuples?

   To repair NPE bugs, a method that selects the 'if' related facts is enough. But the method should be general to handle other types of bugs. Alternatively, should this method not be one-size-fits-all and require customization for specific types of bugs?

2. After identifying 1-minial set of facts that are required for target tuples, which of those facts should be removed to prevent the generation of the target tuples?

   In order to fix NPE bugs, we should remove the negated facts (i.e., add the corresponding positive facts). Similar as 1., do we need to design a general method that can handle other kinds of bugs?