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: It is sunny. If Joseph were a bartender, then it is not sunny. It is late if and only if Joseph is a bartender.
Joseph is not a bartender can be inferred via the modus tollens rule. If it is late, then Joseph is a bartender can be inferred via the biconditional elimination rule. If Joseph were a bartender, then it is late can be inferred via the biconditional elimination rule.