a relation for pruning values of program variables. For example, a C statement <code>if(x){...}</code> is translated to <code>%r=load(x); if(%r){...}</code> in Sil. At the load statement, we record the alias between the values of <code>%r</code> and <code>x</code>, then we can prune not only the value of <code>%r</code>, but also that of <code>x</code> inside the if branch. The <code>java_tmp</code> field is an additional slot for keeping one more alias of temporary variable in Java. The <code>i</code> fiel