Following is a demo of the extra_credit.pl program.
% c:/Users/kchan2/YING/College Work/SUNY Oswego/Fall 2021/CSC 366/COG366WorkSite/prolog/extra_credit.pl compiled 0.00 sec, 17 clauses ?- solve. abigail was born on a monday in february. brenda was born on a wednesday in december. mary was born on a sunday in june. paula was born on a friday in march. tara was born on a saturday in july. true ; false.