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, x is not sad or x will cook. There is at least one x for which x is sad or x will listen to a song. For all x, if x listens to a song, then x is an electrician. For all x, x is not an electrician.
For all x, x will not listen to a song can be inferred via the universal modus tollens rule. There is at least one x for which x will listen to a song or x will cook can be inferred via the existential resolution rule.