SWI-Prolog Did You Know Did you know? the first Prolog interpreter was in Algol-W by Philippe Roussel (1972) Search Documentation:
Pack logtalk -- logtalk-3.90.1/coding/emacs/logtalk-mode/tests

The current version of pack logtalk does not contain a file logtalk-3.90.1/coding/emacs/logtalk-mode/tests