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 or ~s_1. p -> p_11. p_11 -> p.
s_1 -> p can be inferred via the rewriting rule. p <-> p_11 can be inferred via the biconditional introduction rule. p_11 <-> p can be inferred via the biconditional introduction rule.