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: There is at least one x_12 for which x_12 will cook. For all x_12, x_12 will cook if and only if x_12 will drive a car. For all x_12, x_12 is a mechanic.
There is at least one x_12 for which x_12 will cook and x_12 is a mechanic can be inferred via the existential conjunction rule. Some mechanics will cook can be inferred via the existential conjunction rule. For all x_12, if x_12 cooks, then x_12 is driving a car can be inferred via the universal biconditional elimination rule. For all x_12, if x_12 drives a car, then x_12 is cooking can be inferred via the universal biconditional elimination rule.