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_13, x_13 is a mechanic if and only if x_13 will climb a mountain. For all x_13, x_13 will drive a car if and only if x_13 will climb a mountain. For all x_13, x_13 will not play a game or x_13 will drive a car. For all x_13, x_13 will play a game or x_13 is a mechanic.
For all x_13, x_13 is a mechanic or x_13 will drive a car can be inferred via the universal resolution rule. For all x_13, if x_13 were a mechanic, then x_13 is climbing a mountain can be inferred via the universal biconditional elimination rule. For all x_13, if x_13 drives a car, then x_13 is climbing a mountain can be inferred via the universal biconditional elimination rule. For all x_13, if x_13 climbs a mountain, then x_13 is a mechanic can be inferred via the universal biconditional elimination rule. For all x_13, if x_13 climbs a mountain, then x_13 is driving a car can be inferred via the universal biconditional elimination rule.