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: There is at least one x_7 for which x_7 will not play squash or x_7 is a police officer. For all x_7, x_7 will play squash or x_7 will listen to a song. For all x_7, if x_7 were a police officer, then x_7 is an artist. For all x_7, x_7 will listen to a song if and only if x_7 is an artist.
There is at least one x_7 for which x_7 will listen to a song or x_7 is a police officer can be inferred via the existential resolution rule. For all x_7, if x_7 listens to a song, then x_7 is an artist can be inferred via the universal biconditional elimination rule. For all x_7, if x_7 were an artist, then x_7 is listening to a song can be inferred via the universal biconditional elimination rule.