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_11, if x_11 plays squash, then x_11 is not driving a car. For all x_11, x_11 is an electrician if and only if x_11 will play squash. There is at least one x_11 for which x_11 will drive a car.
There is at least one x_11 for which x_11 will not play squash can be inferred via the existential modus tollens rule. For all x_11, if x_11 were an electrician, then x_11 is playing squash can be inferred via the universal biconditional elimination rule. For all x_11, if x_11 plays squash, then x_11 is an electrician can be inferred via the universal biconditional elimination rule.