Strong Differentiation of N-Dimensional Subadditive Processes Takeshi Yoshimoto Indiana University Mathematics Journal 1985 text pdf 10.1512/iumj.1985.34.34042 10.1512/iumj.1985.34.34042 en Indiana Univ. Math. J. 34 (1985) 801 - 808 state-of-the-art mathematics http://iumj.org/access/