What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_1, x_1 is not a police officer. For all x_1, if x_1 were happy, then x_1 is a police officer. For all x_1, x_1 will play squash if and only if x_1 is happy.
For all x_1, x_1 is not happy. For all x_1, if x_1 plays squash, then x_1 is happy. For all x_1, if x_1 were happy, then x_1 is playing squash.