(a) In state of the world ω, Andrew knows that Sally knows the state of nature. Does this imply that Andrew knows the state of nature in ω? Is the fact that Sally knows the state of nature common knowledge among Andrew and Sally in ω?
(b) In every state of the world, Andrew knows that Sally knows the state of nature. Does this imply that Andrew knows the state of nature in every state of the world? Is the fact that Sally knows the state of nature common knowledge among Andrew and Sally in every state of the world?
(c) In state of the world ω, Andrew knows that Sally knows the state of the world. Does this imply that Andrew knows the state of the world in ω? Is the fact that Sally knows the state of the world common knowledge among Andrew and Sally in ω?