Stanford Artificial Intelligence Laboratory
				Computer Science Dept
				Stanford University
				Stanford, California,94305





James Nevins,Associate Director
Draper Lab
75 Cambridge Parkway
Cambridge, Mass, 02142





Dear Jim:



Here are two of the things relevant to descriptors.  One is a definition
of the data types used in defining a part in programs.  The other is the
definition of a particular part, from the Scheinman arm, as it was used
as input into a display program which gave line drawings of the part.  We
are going to use these descriptors for strategies; actually this is somewhat
old, and since there is a new version of GEOMED (geometric editor) with some
bugs, does not run now.  I will dig up another example and send it to you.

I have a paper giving the formalism for such descriptors from 1971, and have
included it with this mailing.  



					With Best Regards



					Thomas O. Binford