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_12, x_12 will not play a game. For all x_12, x_12 will take a plane. For all x_12, if x_12 were an office clerk, then x_12 is a taxi driver. For all x_12, x_12 will go running if and only if x_12 will play a game. For all x_12, x_12 will go running or x_12 is an office clerk.
For all x_12, if x_12 goes running, then x_12 is playing a game can be inferred via the universal biconditional elimination rule. For all x_12, if x_12 plays a game, then x_12 is running can be inferred via the universal biconditional elimination rule. For all x_12, x_12 will not go running can be inferred via the universal biconditional elimination rule.