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: Charles is not rich. Michael is a mechanic if and only if Charles is rich. Michael is a mechanic if and only if it is raining.
If Michael were a mechanic, then Charles is rich can be inferred via the biconditional elimination rule. If Michael were a mechanic, then it is raining can be inferred via the biconditional elimination rule. If Charles were rich, then Michael is a mechanic can be inferred via the biconditional elimination rule. If it rains, then Michael is a mechanic can be inferred via the biconditional elimination rule. Michael is not a mechanic can be inferred via the biconditional elimination rule.