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, if y_2 were a sailor, then y_2 is working. For all y_2, y_2 is not a carpenter. There is at least one y_2 for which y_2 is a bartender if and only if y_2 will work. For all y_2, y_2 is a bartender if and only if y_2 is a carpenter.
For all y_2, if y_2 were a bartender, then y_2 is a carpenter can be inferred via the universal biconditional elimination rule. There is at least one y_2 for which if y_2 were a bartender, then y_2 is working can be inferred via the existential biconditional elimination rule. For all y_2, if y_2 were a carpenter, then y_2 is a bartender can be inferred via the universal biconditional elimination rule. There is at least one y_2 for which if y_2 works, then y_2 is a bartender can be inferred via the existential biconditional elimination rule. For all y_2, y_2 is not a bartender can be inferred via the universal biconditional elimination rule.