What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If Karen reads a book, then David is drinking water. If Susan were a server, then David is drinking water. Sarah is playing squash or Karen is reading a book. Sarah is not playing squash or Susan is a server. If David drinks water, then Karen is reading a book.
If Susan were a server, then Karen is reading a book. Karen is reading a book or Susan is a server. Karen is reading a book if and only if David is drinking water. David is drinking water if and only if Karen is reading a book.