|
MODE R = REF BOOL;
|
|
R r := NIL;
|
|
|
|
MODE U = UNION(BOOL, VOID);
|
|
U u := EMPTY;
|
|
|
|
IF r IS R(NIL) THEN
|
|
print(("r IS NIL", new line))
|
|
ELSE
|
|
print(("r ISNT NIL", new line))
|
|
FI;
|
|
|
|
CASE u IN
|
|
(VOID):print(("u is EMPTY", new line))
|
|
OUT print(("u isnt EMPTY", new line))
|
|
ESAC
|