Samuel Getachew sami9644

CMCDragonkai / even_and_odd.pl

Last active June 7, 2022 02:17

Prolog: Even and Odd

	%% The `=` is Prolog unification operator, it does not perform arithmetic evaluation.
	%% That means `8 = 4 + 4` is false in Prolog.
	%% Instead you can use `8 is 4 + 4` or `8 =:= 4 + 4`.
	%% The unification operator tries to unify intensional structure, and `8 = 4 + 4` is
	%% trying to unify `'+'(4, 4)` with `8`.
	%% However `8 = 8` unifies!

	even(0).
	even(X) :- X > 0, X1 is X - 1, odd(X1).
	even(X) :- X < 0, X1 is X + 1, odd(X1).

kalinchernev / countries

Created October 6, 2014 09:42

Plain text list of countries