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_4, x_4 is not a soldier. For all x_4, x_4 is a taxi driver or x_4 is a lawyer. For all x_4, x_4 is not a lawyer or x_4 will write a letter. For all x_4, x_4 is not a taxi driver or x_4 is a soldier.
For all x_4, x_4 is a lawyer or x_4 is a soldier can be inferred via the universal resolution rule.