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: s -> r_3. s_1 -> s. ~q. r_3 -> s_1. q <-> s_1.
s -> s_1 can be inferred via the transitivity rule. s_1 -> r_3 can be inferred via the transitivity rule. r_3 -> s can be inferred via the transitivity rule. q -> s_1 can be inferred via the biconditional elimination rule. s_1 -> q can be inferred via the biconditional elimination rule. ~s_1 can be inferred via the biconditional elimination rule.