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: ~p_1. s <-> p_1. p and u.
p can be inferred via the simplification rule. u can be inferred via the simplification rule. s -> p_1 can be inferred via the biconditional elimination rule. p_1 -> s can be inferred via the biconditional elimination rule. ~s can be inferred via the biconditional elimination rule.