sig
type st
val start : Ctrlflow.CTRLFLOW.st
val last : Ctrlflow.CTRLFLOW.st
val all : Ctrlflow.CTRLFLOW.st list
val pred : Ctrlflow.CTRLFLOW.st -> Ctrlflow.CTRLFLOW.st list
val succ : Ctrlflow.CTRLFLOW.st -> Ctrlflow.CTRLFLOW.st list
val to_s : Ctrlflow.CTRLFLOW.st -> string
end