You do not have to set up anything special in your .emacs file. In fact, you should make sure that there is nothing in your .emacs file (perhaps left over from a previous class) that refers to Prolog. However, you should put the following line as the first line of any prolog file:
% -*-prolog-*-This tells emacs that that the file contains prolog code and should be edited in prolog mode. When you start a new prolog file you should put this line in the file, then exit emacs, then restart it and re-open the file. You can also manually switch to prolog mode with the command Esc-X prolog-mode <RETURN>. (I.e., hit escape-key x p r o l o g - m o d e return-key.)
To run prolog give emacs the command Esc-X run-prolog<RETURN>
In the emacs buffer where prolog is running, the following special keys are useful:
To read your code into prolog,
RETURN send the current line to prolog ctl-c ctl-u erase back to the prolog prompt ctl-c ctl-p move back to previous input sent to prolog ctl-c ctl-c interrupt prolog (like a single ctl-c when not running under emacs) ctl-h m show a complete list of keys with special meaning in this buffer
to the prolog prompt (note
the period at the end!). followed by a RETURN.
Here is a an example debugging session.