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_7, x_7 is a soldier if and only if x_7 will drive a car. For all x_7, x_7 will drive a car if and only if x_7 will play tennis. There is at least one x_7 for which x_7 will play tennis if and only if x_7 will play a game. For all x_7, x_7 is not a soldier.
For all x_7, if x_7 were a soldier, then x_7 is driving a car can be inferred via the universal biconditional elimination rule. For all x_7, if x_7 drives a car, then x_7 is playing tennis can be inferred via the universal biconditional elimination rule. There is at least one x_7 for which if x_7 plays tennis, then x_7 is playing a game can be inferred via the existential biconditional elimination rule. For all x_7, if x_7 drives a car, then x_7 is a soldier can be inferred via the universal biconditional elimination rule. For all x_7, if x_7 plays tennis, then x_7 is driving a car can be inferred via the universal biconditional elimination rule. There is at least one x_7 for which if x_7 plays a game, then x_7 is playing tennis can be inferred via the existential biconditional elimination rule. For all x_7, x_7 will not drive a car can be inferred via the universal biconditional elimination rule.