Consider the following premises. For all x_9, x_9 is a janitor if and only if x_9 is a taxi driver. There is at least one x_9 for which if x_9 were a janitor, then x_9 is an astronaut. For all x_9, if x_9 were an astronaut, then x_9 is writing a letter. Can we infer the following from them? For all x_9, the fact that x_9 were a taxi driver does not imply that x_9 is writing a letter.
That contradicts the premises. Therefore the answer is no.