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 -> s. p_11 -> p. p_11 <-> s.
p_11 -> s can be inferred via the transitivity rule. p_11 -> s can be inferred via the biconditional elimination rule. s -> p_11 can be inferred via the biconditional elimination rule.