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 x_18, x_18 is a bartender. It is overcast if and only if it is late. It is not overcast.
If it is overcast, then it is late can be inferred via the biconditional elimination rule. If it is late, then it is overcast can be inferred via the biconditional elimination rule. It is not late can be inferred via the biconditional elimination rule.