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_23, if x_23 were a musician, then x_23 is listening to a song. For all x_23, if x_23 listens to a song, then x_23 is a politician. For all x_23, if x_23 were a politician, then x_23 is listening to a song. Karen is a musician.
There is at least one x for which x is a musician can be inferred via the existential generalization rule. For all x_23, if x_23 were a musician, then x_23 is a politician can be inferred via the universal transitivity rule. For all x_23, x_23 will listen to a song if and only if x_23 is a politician can be inferred via the universal biconditional introduction rule. For all x_23, x_23 is a politician if and only if x_23 will listen to a song can be inferred via the universal biconditional introduction rule.