Pseudo-ring

From HandWiki

In mathematics, and more specifically in abstract algebra, a pseudo-ring is one of the following variants of a ring:

  • A rng, i.e., a structure satisfying all the axioms of a ring except for the existence of a multiplicative identity.[1]
  • A set R with two binary operations + and ⋅ such that (R, +) is an abelian group with identity 0, and a(b + c) + a0 = ab + ac and (b + c)a + 0a = ba + ca for all a, b, c in R.[2]
  • An abelian group (A, +) equipped with a subgroup B and a multiplication B × AA making B a ring and A a B-module.[3]

None of these definitions are equivalent, so it is best to avoid the term "pseudo-ring" or to clarify which meaning is intended.

See also

  • Semiring – an algebraic structure similar to a ring, but without the requirement that each element must have an additive inverse

References

  1. Bourbaki, N. (1998). Algebra I, Chapters 1-3. Springer. p. 98. 
  2. Natarajan, N. S. (1964). "Rings with generalised distributive laws". J. Indian. Math. Soc.. New Series 28: 1–6. 
  3. Patterson, Edward M. (1965). "The Jacobson radical of a pseudo-ring". Math. Z. 89 (4): 348–364. doi:10.1007/bf01112167.