What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_6, x_6 is not a cashier. For all x_6, if x_6 were a cashier, then x_6 is reading a book. For all x_6, if x_6 plays squash, then x_6 is reading a book. For all x_6, if x_6 reads a book, then x_6 is a cashier. For all x_6, if x_6 reads a book, then x_6 is playing squash.
For all x_6, x_6 will not read a book. For all x_6, if x_6 were a cashier, then x_6 is playing squash. For all x_6, if x_6 plays squash, then x_6 is a cashier. For all x_6, x_6 is a cashier if and only if x_6 will read a book. For all x_6, x_6 will play squash if and only if x_6 will read a book. For all x_6, x_6 will read a book if and only if x_6 is a cashier. For all x_6, x_6 will read a book if and only if x_6 will play squash.