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: For all x_13, if x_13 makes tea, then x_13 is excited. John is excited or Charles is not cooking. John is making tea or Charles is cooking. For all x_13, if x_13 were excited, then x_13 is making tea.
If Charles cooks, then John is excited can be inferred via the rewriting rule. For all x_13, x_13 will make tea if and only if x_13 is excited can be inferred via the universal biconditional introduction rule. For all x_13, x_13 is excited if and only if x_13 will make tea can be inferred via the universal biconditional introduction rule.