sig
type l
val bot : Dataflow.LATTICE.l
val top : Dataflow.LATTICE.l
val meet : Dataflow.LATTICE.l -> Dataflow.LATTICE.l -> Dataflow.LATTICE.l
val compare : Dataflow.LATTICE.l -> Dataflow.LATTICE.l -> int
val to_s : Dataflow.LATTICE.l -> string
end