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: p. p_1. p_13 <-> p_1.
p and p_1 can be inferred via the conjunction rule. p_1 and p can be inferred via the conjunction rule. p_13 -> p_1 can be inferred via the biconditional elimination rule. p_1 -> p_13 can be inferred via the biconditional elimination rule.