Solutions

a <- b & g.
b <- c & d.
b <- e.
c.
d <- f.
f.

1. Give a model of the knowledge base.

   One model is where c, f, d and b are true and a, e and g are false.

   Another model is where every atom is true.

2. Give an interpretation that is not a model of the knowledge base.

   We can select an clause and falsify it, filling the other atoms arbitrarily. For example, the interpretion with a false and every other atom true falsifies the first clause and isn't a model.

3. Give two atoms that are logical consequences of the knowledge base.

   Any two of c, f, d and b.

4. Give two atoms that are not logical consequences of the knowledge base.

   Any two of a, e and g.