Extensions and s-comparability of exchange rings

Let S be a ring extension of R. In this note, for any positive integer s we study s-comparability related to ring extensions. We show that if S is an excellent extension of R, R and S are exchange rings, and R has the n-unperforation property. R satisfies s-comparability if and we only if so does S , and we prove that for a 2-sided ideal J of S , and an exchange subring R of the exchange ring S , which contains J as a direct summand, then R satisfies s-comparability if and only if so does R/J .