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 y, y is not a mechanic. For all y, y will drive a car if and only if y is a doctor. For all y, y is a mechanic if and only if y is a doctor. For all y, y will drive a car or y is a soldier.
For all y, if y drives a car, then y is a doctor can be inferred via the universal biconditional elimination rule. For all y, if y were a mechanic, then y is a doctor can be inferred via the universal biconditional elimination rule. For all y, if y were a doctor, then y is driving a car can be inferred via the universal biconditional elimination rule. For all y, if y were a doctor, then y is a mechanic can be inferred via the universal biconditional elimination rule. For all y, y is not a doctor can be inferred via the universal biconditional elimination rule.