 Now, assume that the hen is always clucking, but that the dog never barks, and that although Zoe has acute hearing, she cannot see the yard. Then there are certain possible worlds that Zoe cannot distinguish: possible ways things may be which she cannot tell apart. For example, being in the world with only a hen \((p,\neg q)\), Zoe cannot tell if she is in the world with both hen and dog \((p,q)\): her situation is such that Zoe is aware of two ways things could be but her information does not allow her to eliminate either.