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 is a sailor. For all y, y will work if and only if y is a sailor.
For all y, if y works, then y is a sailor can be inferred via the universal biconditional elimination rule. For all y, if y works, then y is a sailor can be inferred via the universal biconditional elimination rule. For all y, if y were a sailor, then y is working can be inferred via the universal biconditional elimination rule. For all y, if y were a sailor, then y is working can be inferred via the universal biconditional elimination rule.