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_17 for which x_17 is not a doctor or x_17 is bored. For all x_17, if x_17 were a taxi driver, then x_17 is listening to a song. For all x_17, if x_17 listens to a song, then x_17 is a taxi driver. For all x_17, x_17 will play squash. For all x_17, x_17 is a doctor or x_17 will listen to a song. For all x_17, x_17 is not a taxi driver.
For all x_17, x_17 will not listen to a song can be inferred via the universal modus tollens rule. There is at least one x_17 for which x_17 will listen to a song or x_17 is bored can be inferred via the existential resolution rule. For all x_17, x_17 is a taxi driver if and only if x_17 will listen to a song can be inferred via the universal biconditional introduction rule. For all x_17, x_17 will listen to a song if and only if x_17 is a taxi driver can be inferred via the universal biconditional introduction rule.