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 <-> r_1. r_1 or ~q_7. q or q_7.
q_7 -> r_1 can be inferred via the rewriting rule. q -> r_1 can be inferred via the biconditional elimination rule. r_1 -> q can be inferred via the biconditional elimination rule.