What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_11, if x_11 takes a plane, then x_11 is a doctor. For all x_11, if x_11 were a doctor, then x_11 is a musician. For all x_11, x_11 is a writer if and only if x_11 will take a plane. There is at least one x_11 for which if x_11 were a janitor, then x_11 is a writer.
For all x_11, if x_11 takes a plane, then x_11 is a musician. For all x_11, if x_11 were a writer, then x_11 is taking a plane. For all x_11, if x_11 takes a plane, then x_11 is a writer.