🚀 go-pugleaf

I'm looking for a good public domain prolog for use in teaching my AI
class.  Currently, we're using PD-Prolog which is not sufficient for this 
class due to its lack of many basic features (like tracing!).  What I
need is the following:

	a. Run under MS/DOS
	b. Follow Clocksin/Mellish syntax, more or less
	c. Have a sufficient feature set to be able to do some 
		interesting projects
	d. Be cheap or free, so that the students can afford it.
	e. Be free of large bugs.
	
There must be some out there, so please give me a call or send me 
e-mail if you know of one.

	Thanks for any help,
	
	--Kim Tracy, AT&T Bell Laboratories and 
	Illinois Institute of Technology
	...att!ihlpa!tracy
	(708) 979-4164