do env <- dualLiveness emptyBlockSet g
let lookup id = lookupBlockEnv env id `orElse` fact_bot dualLiveLattice
f' dual z = f (on_stack dual) z
do env <- dualLiveness emptyBlockSet g
let lookup id = lookupBlockEnv env id `orElse` fact_bot dualLiveLattice
f' dual z = f (on_stack dual) z