訂正日: 2006/09/29訂正理由: -訂正箇所: 引用文献情報訂正内容: Right : [1] L. Hörmander, Pseudo-differential operators and hypoelliptic equations, Proc. Symp. on Singular Integrals, Amer. Math. Soc., 10 (1967), 138-183. [2] A. W. Knapp and E. M. Stein, Singular integrals and the principal series, Proc. Nat. Acad. Sci., 63 (1969), 281-284. [3] M. Nagase and K. Shinkai, Complex powers of non-elliptic operators, to appear.