Suppose that R is a CM local ring, and I and J are two ideals of R. We say that I is algebraically linked to J if there is an R-sequence x in $I \cap J$ such that I = x : J and J = x : I.
In some articles about algebraic linkage theory, when I and J are two linked ideals, they say: We may apply the usual method of argument in the linkage theory to reduce the proof to the case in which I = 0 : J and J = 0 : I with ht I = ht J = 0.
Question: What is this ''usual method of argument in the linkage theory'' ?