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: Karen is climbing a mountain or Michael is not playing a game. For all x_13, if x_13 plays squash, then x_13 is climbing a mountain. For all x_13, if x_13 climbs a mountain, then x_13 is playing squash.
If Michael plays a game, then Karen is climbing a mountain can be inferred via the rewriting rule. For all x_13, x_13 will play squash if and only if x_13 will climb a mountain can be inferred via the universal biconditional introduction rule. For all x_13, x_13 will climb a mountain if and only if x_13 will play squash can be inferred via the universal biconditional introduction rule.