ISETL
Interactive SETL by Gary Levin <gary@clutx.clarkson.edu>.
Binaries and source for MS-DOS, Macintosh, Unix, VAX/VMS.
[Clarkson U. "An Introduction to ISETL Version 1.9", G.M. Levin, Dept MCS, Clarkson U].
["Learning discrete mathematics with ISETL", Nancy Baxter. Ed. Gary Levin Dubinsky. Springer-Verlag, c.1989.]
(Apr 1994)