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 will work if and only if y will make tea. There is at least one y for which if y makes tea, then y is working. For all y, if y makes tea, then y is working.
For all y, if y works, then y is making tea can be inferred via the universal biconditional elimination rule. For all y, if y makes tea, then y is working can be inferred via the universal biconditional elimination rule.