var x, y, n;

procedure fib;
var tmp;
begin
    if n # 0 then
    begin
        write y;
        tmp := y;
        y := y + x;
        x := tmp;
        n := n - 1;
        call fib
    end
end;

begin
    x := 0 ; y := 1 ; n := 10 ; call fib
end.
Add a test PL/0 code.
Add a test PL/0 code.
