What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_9, x_9 will play squash. For all x_9, x_9 will write a letter if and only if x_9 will play squash. For all x_9, x_9 is rich.
For all x_9, x_9 will play squash and x_9 is rich. For all x_9, x_9 is rich and x_9 will play squash. For all x_9, if x_9 writes a letter, then x_9 is playing squash. For all x_9, if x_9 plays squash, then x_9 is writing a letter.