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_2, x_2 is a carpenter or x_2 is sad. For all x_2, if x_2 were a carpenter, then x_2 is cooking. For all x_2, x_2 will cook or x_2 is not sad.
For all x_2, if x_2 were sad, then x_2 is cooking can be inferred via the universal rewriting rule.