Suppose R is a ring with identity element 1 and k is a positive integer. Let H (k, R) denote the set of kth powers of elements of R, and let J(k, R) denote the additive subgroup of R generated by H(k, R). If Z denotes the ring of integers, thenG(k, R) = {a∊Z: aR ⊆ J(k, R)}is an ideal of Z.
展开▼