What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_9, x_9 is not a mechanic or x_9 will cook. For all x_9, if x_9 cooks, then x_9 is writing a letter. For all x_9, if x_9 writes a letter, then x_9 is a carpenter. For all x_9, if x_9 were a carpenter, then x_9 is writing a letter. For all x_9, x_9 will listen to a song or x_9 is a mechanic. For all x_9, x_9 will not listen to a song or x_9 is a carpenter.
For all x_9, if x_9 cooks, then x_9 is a carpenter. For all x_9, x_9 is a mechanic or x_9 is a carpenter. For all x_9, x_9 will write a letter if and only if x_9 is a carpenter. For all x_9, x_9 is a carpenter if and only if x_9 will write a letter.