bodies :: [Rule] -> Atom -> [[Literal]]
-- returns all bodies of rules with the atom as head
bodies p a  = [ body r | r<-p , (kopf r)==a ]
bodies :: [Rule] -> Atom -> [[Literal]]
bodies p a  = [ body r | r<-p , (kopf r)==a ]
bodies p a  = [ body r | r<-p , (kopf r)==a ]