:- module(adb_pfc,[]). :- use_module(library(logicmoo_user)). ~P,P ==> contrradiction. bird(X), \+ ~fly(X) ==> fly(X). penguin(X) ==> bird(X). penguin(X) ==> ~fly(X). bird(X), injured(X) ==> ~fly(X). bird(X), dead(X) ==> ~fly(X).