We develop the foundations for graded equivalence theory and apply the
m to investigate properties such as primeness, finite representation t
ype, and vertex theory of graded rings. The key fact that we prove is
that, for any two G-graded rings R and S such that there is a category
equivalence from gr(R) to gr(S) that commutes with suspensions, then,
for any subgroup H of G, the categories gr(H/G, R) and gr(H/G, S) of
modules graded by the G-set of right cosets are also equivalent. (C) 1
995 Academic Press, Inc.