Reasoner example for birds

% (lbird & -abnormal_bird) => lflies
-lbird(X,L) | abnormal_bird(X) | lflies(X,likely).

-bird(X) | lbird(X,certain).
-lbird(X,certain) | bird(X).

-penguin(X) | bird(X).

% -abnormal_bird(tweety).

-lflies(tweety,L) | ans(L).

-penguin(X) | abnormal_bird(X).

-seagull(X) | normal_bird(X).

-abnormal_bird(X) | -normal_bird(X).

seagull(tweety).

bird(tweety).
penguin(pengu).

-lflies(pengu,L) | ans(L).