As luck would have it there is a lemma list for use with WordSmith Tools,
kindly supplied by "SOMEYA, Yasumasa" <ysomeya@gol.com> and downloadable as
of the last few days from the website addresses below. The format is not
exactly what you ask for: it's
abandon -> abandons,abandonment,abandoned
etc. but it may be helpful. I think Yasumasa may update it but write to him
if you need more.
Best wishes -- Mike
******************************************
Mike Scott
Applied English Language Studies Unit
University of Liverpool, Liverpool L69 3BX
http://www.liv.ac.uk/~ms2928/homepage.html
http://www.liv.ac.uk/~ms2928/wordsmith/index.htm