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_6, if x_6 were poor, then x_6 is rich. There is at least one x_6 for which if x_6 were an electrician, then x_6 is writing a letter. For all x_6, if x_6 were rich, then x_6 is writing a letter. For all x_6, x_6 is not an artist or x_6 is an electrician. For all x_6, x_6 is an artist or x_6 is poor.
For all x_6, if x_6 were poor, then x_6 is writing a letter can be inferred via the universal transitivity rule. For all x_6, x_6 is poor or x_6 is an electrician can be inferred via the universal resolution rule.