The link to Naumowicz and Bylinski's "Improving mizar texts with Properties and Requirements" on http://www.mizar.org/project/bibliography.html is broken -- I got a 404 error when I tried to follow that link. A working link is http://www.springerlink.com/content/72cdg95ndd3ywgl8/ Jesse -- Jesse Alama (alama@stanford.edu) *393: Incorrect beginning of a reasoning item