fun in_set(bb: BasicBlock): nullable S is abstract
fun out_set(bb: BasicBlock): nullable S is abstract
fun in_set=(bb: BasicBlock, s: S) is abstract
fun out_set=(bb: BasicBlock, s: S) is abstract
fun in_set(bb: BasicBlock): nullable S is abstract
fun out_set(bb: BasicBlock): nullable S is abstract
fun in_set=(bb: BasicBlock, s: S) is abstract
fun out_set=(bb: BasicBlock, s: S) is abstract