winter 1999 by Matt Franklin <startled@leland.stanford.edu>,
Greg Hutchins <gmh@leland.stanford.edu>, Yu Ping Hu
<yph@cs.stanford.edu>. Modified by arens. */
winter 1999 by Matt Franklin <startled@leland.stanford.edu>,
Greg Hutchins <gmh@leland.stanford.edu>, Yu Ping Hu
<yph@cs.stanford.edu>. Modified by arens. */