11. However, it is possible for a ring without identity to lack modular right ideals entirely. 12. Right ideals , left ideals, and two-sided ideals other than these are called " nontrivial ".13. Similarly, a right multiplications-invariant subring is a right ideal . 14. By the above paragraph, we find that " I " is a maximal right ideal . 15. The Human Rights ideal imparts the international benchmark that states can have related and common ideas. 16. It follows from condition ( 3 ) that every left or right ideal is a subalgebra. 17. Every prime principal right ideal ring is isomorphic to a matrix ring over a right Ore domain. 18. Since rings with unity always have a maximal right ideal , a right uniserial ring is necessarily local. 19. A " two-sided ideal " is a subset that is both a left and a right ideal . 20. Maximal right ideals are defined similarly.