1program sets (input, output);
2type
3 Color = (RED, BLUE, GREEN);
4 ColorSet = set of Color;
5var
6 s : ColorSet;
7
8procedure p (var s : ColorSet);
9begin
10 s := [RED, BLUE];
11end;
12
13begin
14 p(s);
15 if BLUE in s then begin
16 s := s - [BLUE];
17 end;
18end.
19