Prolog Compilers, Interpreters

There is one that actually runs in your browser window if you have a Java-enabled browser. Click here, scroll down to "the distribution," and click on the button labelled "Start W-Prolog" to start the prolog interpreter Applet.

Copy the text of the facts and rules from the previous post, and run a query to see if terach is the father of yishmael.

There are some free compilers and interpreters here.