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 z_4, z_4 is not a cashier. Patricia is a cashier if and only if it is cold.
If Patricia were a cashier, then it is cold can be inferred via the biconditional elimination rule. If it is cold, then Patricia is a cashier can be inferred via the biconditional elimination rule.