The Weyl-von Neumann Theorem for Approximately Finite C-Algebras F. Thayer Indiana University Mathematics Journal 1975 text pdf 10.1512/iumj.1975.24.24069 10.1512/iumj.1975.24.24069 en Indiana Univ. Math. J. 24 (1975) 875 - 877 state-of-the-art mathematics http://iumj.org/access/