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_4 and q. s_4 -> p_6. p_6 -> s_4.
s_4 can be inferred via the simplification rule. q can be inferred via the simplification rule. s_4 <-> p_6 can be inferred via the biconditional introduction rule. p_6 <-> s_4 can be inferred via the biconditional introduction rule.