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 is a poet. For all y_2, y_2 is an office clerk if and only if y_2 is a nurse. There is at least one y_2 for which y_2 is an office clerk.
There is at least one y_2 for which y_2 is an office clerk and y_2 is a poet can be inferred via the existential conjunction rule. There is at least one y_2 for which y_2 is a poet and y_2 is an office clerk can be inferred via the existential conjunction rule. For all y_2, if y_2 were an office clerk, then y_2 is a nurse can be inferred via the universal biconditional elimination rule. For all y_2, if y_2 were a nurse, then y_2 is an office clerk can be inferred via the universal biconditional elimination rule.