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, if x_7 were poor, then x_7 is drinking water. There is at least one x_7 for which x_7 will listen to a song or x_7 will not drink water. For all x_7, if x_7 were rich, then x_7 is poor.
For all x_7, if x_7 were rich, then x_7 is drinking water can be inferred via the universal transitivity rule. There is at least one x_7 for which if x_7 drinks water, then x_7 is listening to a song can be inferred via the existential rewriting rule.