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: forall x_13: R_13(x_13) -> S_13(x_13). t or R_13(a_13). ~t or s_1. s_1 <-> S_13(a_13).
R_13(a_13) or s_1 can be inferred via the resolution rule. R_1(a_13) -> t can be inferred via the rewriting rule. s_1 -> S_13(a_13) can be inferred via the biconditional elimination rule. S_13(a_13) -> s_1 can be inferred via the biconditional elimination rule.