What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_18, x_18 will read a book. For all x_18, if x_18 plays squash, then x_18 is reading a book. For all x_18, if x_18 reads a book, then x_18 is playing squash.
For all x_18, x_18 will play squash. For all x_18, x_18 will play squash if and only if x_18 will read a book. For all x_18, x_18 will read a book if and only if x_18 will play squash.