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_2, y_2 will climb a mountain if and only if y_2 is a lawyer. For all y_2, y_2 will climb a mountain if and only if y_2 is a lawyer.
For all y_2, if y_2 climbs a mountain, then y_2 is a lawyer can be inferred via the universal biconditional elimination rule. For all y_2, if y_2 climbs a mountain, then y_2 is a lawyer can be inferred via the universal biconditional elimination rule. For all y_2, if y_2 were a lawyer, then y_2 is climbing a mountain can be inferred via the universal biconditional elimination rule. For all y_2, if y_2 were a lawyer, then y_2 is climbing a mountain can be inferred via the universal biconditional elimination rule.