lookup id = lookupBlockEnv env id `orElse` fact_bot dualLiveLattice
f' dual z = f (on_stack dual) z
in fold_edge_facts_b f' dualLiveness g lookup z
lookup id = lookupBlockEnv env id `orElse` fact_bot dualLiveLattice
f' dual z = f (on_stack dual) z
in fold_edge_facts_b f' dualLiveness g lookup z