fix invalid post-order for tree interpolation with Princess.
The order of child-nodes in the tree was reversed.
The bug exists since This is quite a long time.
Using "prepend" (`+=:`) instead of "append" (`+=`) solves the problem.
@@ -160,7 +160,7 @@ class PrincessInterpolatingProver extends PrincessAbstractProver<Integer, Intege
// otherwise: leaf-node -> start new subtree, no children
while (!subtreeStarts.isEmpty() && start <= subtreeStarts.peek()) {
subtreeStarts.pop();
- children.$plus$eq(stack.pop());
+ children.$plus$eq$colon(stack.pop()); // prepend
}
subtreeStarts.push(start);
stack.push(new Tree<>(asScala(partitionedFormulas.get(i)).toSet(), children.toList()));
