program s402;
var
a, b : integer;
x, y : ^integer;
procedure fun(a, b : integer);
var
k : integer;
begin
k := a;
a := b;
b := k;
end;
begin
a := 3;
b := 6;
x := @a;
y := @b;
fun(x^, y^);
write('No.1:', a, ',', b, ' ');
fun(a, b);
writeln('No.2:', a, ',', b);
end. 输出: 1