class virtualUse[['a, 'b]]
start :object
..end
inherit ['i, 'o] start
to derive a class to represent the
initial state of a machine. It's start
method initiates the machine
with the virtual private guard
method.method private virtual guard : ('a, 'b, unit) guard
method start : ('a, 'b, unit) t
start (guard self#guard)
.