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 late if and only if Joseph is rich. Joseph is not rich. Michael is making tea if and only if it is late.
If it is late, then Joseph is rich can be inferred via the biconditional elimination rule. If Michael makes tea, then it is late can be inferred via the biconditional elimination rule. If Joseph were rich, then it is late can be inferred via the biconditional elimination rule. If it is late, then Michael is making tea can be inferred via the biconditional elimination rule. It is not late can be inferred via the biconditional elimination rule.