%%%% File: dinnerware %% Facts % cutlery(N,soup(A)) :: N is the name of the cutlery and A is whether it can be used for soup cutlery(knife,soup(no)). cutlery(fork,soup(no)). cutlery(spoon,soup(yes)). cutlery(chopsticks,soup(yes)). % dish(N,soup(A)) :: N is the name of the dish and A is whether it can be used for soup dish(plate,soup(no)). dish(bowl,soup(yes)). dish(cup,soup(yes)). dish(saucecup,soup(no)). %% Rules % soup :: all items that are cutlery cutlery :- cutlery(Name,_),write(Name),nl,fail. cutlery. % dishes :: all items that are dishes dishes :- dish(Name,_),write(Name),nl,fail. dishes. % dinnerware :: all items that are flatware dinnerware :- cutlery,dishes. % soupable(Name) :: Name can eat soup soupable(Name) :- cutlery(Name,soup(yes)). soupable(Name) :- dish(Name,soup(yes)). % pair(C,D) :: C is a cutlery that can be paired with D to eat soup pair(C,D) :- cutlery(C,soup(yes)),dish(D,soup(yes)). % nsfs(C,D) :: Neither C or D are safe for eating soup with nsfs(C,D) :- cutlery(C,soup(no)),dish(D,soup(no)). % exit :: exits swipl with the correct command for exiting exit :- halt.