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: There is at least one z_3 for which z_3 is not a lawyer. For all z_3, z_3 is happy and z_3 will make tea. For all z_3, z_3 is a lawyer or z_3 will listen to a song.
There is at least one z_3 for which z_3 will listen to a song can be inferred via the existential disjunctive syllogism rule. For all z_3, z_3 is happy can be inferred via the universal simplification rule. For all z_3, z_3 will make tea can be inferred via the universal simplification rule.