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 or p. ~q. q_2 <-> p.
p can be inferred via the disjunctive syllogism rule. q_2 -> p can be inferred via the biconditional elimination rule. p -> q_2 can be inferred via the biconditional elimination rule.