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