What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: For all x_3, x_3 will drink water if and only if x_3 will play squash. For all x_3, x_3 is a police officer or x_3 will not drink water.
For all x_3, if x_3 drinks water, then x_3 is a police officer can be inferred via the universal rewriting rule. For all x_3, if x_3 drinks water, then x_3 is playing squash can be inferred via the universal biconditional elimination rule. For all x_3, if x_3 plays squash, then x_3 is drinking water can be inferred via the universal biconditional elimination rule.