with text_io; use text_io;
procedure LinKer is
	s: constant STRING := "Hello World!";
	c: constant CHARACTER := 'o';
	p: NATURAL := s'FIRST-1;
	v, l: BOOLEAN := false;
begin
	while (not v) and then (not l) loop
		v := (p+1 >= s'LAST);
		l := (s(p+1) = c);
		p := p+1;
	end loop;
	if l	then Put_Line("megvan...");
		else Put_Line("nincs...");
	end if;
end lINkER;