Someone

VAR i : INTEGER;

FUNCTION foo(REF c : INTEGER) : INTEGER;
BEGIN
        c := c * 2;
        COUT << "c = " << c << NL;
        RETURN 1;
END foo;

BEGIN
i := 3;
foo(i);
COUT << "i = " << i << NL;
RETURN 3;
END.

============================ OUTPUTS:
  C = 6
  i = 6
============================


VAR i : INTEGER;

FUNCTION foo2(REF z : INTEGER) : INTEGER;
BEGIN
        z := z * 2;
        COUT << "z = " << z << NL;
        RETURN 1;
END foo2;

FUNCTION foo(REF c : INTEGER) : INTEGER;
BEGIN
        RETURN foo2(c);
END foo;

BEGIN
i := 5;
COUT << "i = " << foo(i) << NL;
RETURN 3;
END.    

============================ OUTPUTS:
i = z = 10
1
============================