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_14, if x_14 listens to a song, then x_14 is a mechanic. For all x_14, x_14 is not a mechanic. There is at least one x_14 for which x_14 will listen to a song or x_14 is bored. For all x_14, if x_14 were a mechanic, then x_14 is listening to a song.
For all x_14, x_14 will not listen to a song can be inferred via the universal modus tollens rule. For all x_14, x_14 will listen to a song if and only if x_14 is a mechanic can be inferred via the universal biconditional introduction rule. For all x_14, x_14 is a mechanic if and only if x_14 will listen to a song can be inferred via the universal biconditional introduction rule.