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_14, x_14 is fast and x_14 will listen to a song. There is at least one x_14 for which x_14 is a nurse. For all x_14, x_14 is a soldier.
For all x_14, x_14 is fast can be inferred via the universal simplification rule. For all x_14, x_14 will listen to a song can be inferred via the universal simplification rule. Some nurses are soldiers can be inferred via the existential conjunction rule. Some soldiers are nurses can be inferred via the existential conjunction rule.