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, x_6 is happy. For all x_6, x_6 is not a scientist. For all x_6, if x_6 were happy, then x_6 is listening to a song. For all x_6, x_6 is a scientist or x_6 is an astronaut.
For all x_6, x_6 will listen to a song can be inferred via the universal modus ponens rule. For all x_6, x_6 is an astronaut can be inferred via the universal disjunctive syllogism rule.