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_10: ~R_10(x_10). u <-> s_4. R_10(h_1) <-> s_4.
u -> s_4 can be inferred via the biconditional elimination rule. R_10(h_1) -> s_4 can be inferred via the biconditional elimination rule. s_4 -> u can be inferred via the biconditional elimination rule. s_4 -> R_10(h_1) can be inferred via the biconditional elimination rule.