Group Ring
The set of sums sum_(x)a_xx ranging over a multiplicative group and a_i are elements of a field with all but a finite number of a_i=0. Group rings are graded algebras.
See also
Graded Algebra, Group AlgebraExplore with Wolfram|Alpha
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Cite this as:
Weisstein, Eric W. "Group Ring." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/GroupRing.html