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 z, z is a soldier or z is not sad. For all z, z is sad or z is not a soldier.
For all z, if z were sad, then z is a soldier can be inferred via the universal rewriting rule. For all z, if z were a soldier, then z is sad can be inferred via the universal rewriting rule.