List of unknowns that should be queried again when the argument unknown has shrunk to bot, to eagerly trigger (analysis-time!) abstract garbage collection idependently of reach-based pruning at the end.
Stemmler, F., Schwarz, M., Erhard, J., Tilscher, S., Seidl, H. Taking out the Toxic Trash: Recovering Precision in Mixed Flow-Sensitive Static Analyses