ref: 6ae2e2bb7bebdc3f4d450f1ddc6c69a02c3f4998
dir: /example.pl/
:- dynamic(math/4).
math(A,B,C,D) :- D is A + B + C * A.
true.
likes(bob, ice).
likes(sam, text).
likes(sam, ice).
could_be_friends(Person1, Person2) :-
likes(Person1, Thing1),
likes(Person2, Thing2),
Thing1 = Thing2.
list1(A) :- A = [1,2,3,4].
list2(A) :- A = [a,b|c].
curly(A) :- A = {one,two,three}.