A subring of a ring is a subgroup of that is closed under multiplication.
Subring
See also
Ring, SubgroupExplore with Wolfram|Alpha
References
Dummit, D. S. and Foote, R. M. Abstract Algebra, 2nd ed. Englewood Cliffs, NJ: Prentice-Hall, p. 230, 1998.Referenced on Wolfram|Alpha
SubringCite this as:
Weisstein, Eric W. "Subring." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Subring.html