ValueVarEx: obj
Point:
%abstract
%immutable
in x: var integer
in y: var integer
+:
in P: ref Point
out V: ref Point
print:
PointValue: Point
%immutable
PointVar: Point
:=:
in P: ref Point -- here is a ref to a Point Var or Value
P1: obj PointValue(,)
P2: obj PointVar(,)