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: ~q_8. q_15 -> r_15. q <-> q_8. r_3 or q_15. r_3 -> r_15.
r_15 can be inferred via the disjunction elimination rule. q -> q_8 can be inferred via the biconditional elimination rule. q_8 -> q can be inferred via the biconditional elimination rule. ~q can be inferred via the biconditional elimination rule.