tests/t15.p

program main(output);
const
        size = 10;
var
        aset: set of 1..size;
        i, j: integer;
begin
        aset := [];
        for i := 1 to size do
        begin
                aset := [i]+aset;
                for j := 1 to size do
                        if j in aset then
                                writeln(i,j);
        end;
end.