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 sad, then x_6 is an electrician. For all x_6, if x_6 goes running, then x_6 is not an electrician. For all x_6, x_6 is an electrician or x_6 is not a musician. For all x_6, x_6 is a musician or x_6 is sad.
For all x_6, if x_6 were a musician, then x_6 is an electrician can be inferred via the universal rewriting rule.