You can retrieve source code for the Trepan algorithm from: http://www.biostat.wisc.edu/~craven/trepan.sh http://www.biostat.wisc.edu/~craven/TrepanWin.zip The first file is a UNIX shell archive that contains the code, a ReadMe file, and an example data set. The second is the same, except it is for Microsoft Windows. A paper on Trepan can be found via: http://www.cs.wisc.edu/~shavlik/abstracts/craven.nips96.ps.abstract.html Please cite that paper if you use Trepan in your research. (Additional details are in Mark Craven's PhD thesis: http://www.cs.wisc.edu/~shavlik/abstracts/craven.thesis.ps.abstract.html ) JWS 7/14/00