What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_10, if x_10 writes a letter, then x_10 is a taxi driver. There is at least one x_10 for which x_10 will write a letter or x_10 is not an astronaut. For all x_10, if x_10 writes a letter, then x_10 is an astronaut.
There is at least one x_10 for which if x_10 were an astronaut, then x_10 is writing a letter.