[algebra] In mathematics, and more specifically in abstract algebra, a rng (or pseudo-ring or non-unital ring) is an algebraic structure satisfying the same properties as a ring, without assuming the existence of a multiplicative identity. The term `rng` (pronounced rung) is meant to suggest that it is a `ring` without `i`, i.e. without the... Found on http://en.wikipedia.org/wiki/Rng_(algebra)