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, if x takes a plane, then x is listening to a song. For all x, x will read a book if and only if x will take a plane. For all x, if x listens to a song, then x is reading a book.
For all x, if x takes a plane, then x is reading a book can be inferred via the universal transitivity rule. For all x, if x reads a book, then x is taking a plane can be inferred via the universal biconditional elimination rule. For all x, if x takes a plane, then x is reading a book can be inferred via the universal biconditional elimination rule.