The 1954 Statelessness Status Convention provided a definition of a stateless person (which has since become part of customary international law, according to the International Law Commission), and sets out a number of rights that stateless persons should enjoy.
The ratio of two integers P and Q can be expressed as P : Q or P/Q. In both cases, you may divided P and Q by their greatest common factor so as to express the ratio in its simplest form.
Any number that is not rational. An irrational number cannot be written as the ratio. of two integers.