NullList: obj
Node:
ex: var char
x: ref Node
isNull:<
out V: var Boolean
scan:< Object
append:<
add:<
Interior: Node
in e: var char
elm: var char
next: ref Node
scan::
append::
Null: Node
d: var integer
isNull::
add::
S: ref Interior
List:
first: ref Node
last: ref Node
Add:
in e: var char
S: ref Interior
scan:
L: obj List