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_7, x_7 is a taxi driver and x_7 is a soldier. For all x_7, if x_7 were a mechanic, then x_7 is not a taxi driver. There is at least one x_7 for which if x_7 cooks, then x_7 is a mechanic.
For all x_7, x_7 is a taxi driver can be inferred via the universal simplification rule. For all x_7, x_7 is a soldier can be inferred via the universal simplification rule.