Reasoner another example for birds

% (lbird & -lflies(certain)) =>  lflies(likely)

-lbird(X,L) |  notflies(X) |  lflies(X,likely).

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

-penguin(X) | bird(X).

-penguin(X) | notflies(X).

-notflies(X) | -lflies(X,Y).



bird(tweety).
penguin(pengu).

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