Differential Operators of Infinite Order on a Lie Group I R. Goodman Indiana University Mathematics Journal 1970 text pdf 10.1512/iumj.1970.19.19069 10.1512/iumj.1970.19.19069 en Indiana Univ. Math. J. 19 (1970) 879 - 894 state-of-the-art mathematics http://iumj.org/access/