In 1985 Xerox announced support for Prolog on its AI workstations and awarded development to Quintus, which delivered the Xerox Quintus Prolog implementation fully integrated with Interlisp-D.
http://www.bitsavers.org/pdf/xerox/interlisp-d/newsletters/AIDispatch_Aug85.pdf#page=9
https://softwarepreservation.computerhistory.org/prolog/#Quintus