What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_12, x_12 is an office clerk if and only if x_12 is a doctor. For all x_12, x_12 will not drink water. For all x_12, x_12 will drink water if and only if x_12 is an office clerk. Jennifer is a doctor if and only if Robert is writing a letter.
If Jennifer were a doctor, then Robert is writing a letter. If Robert writes a letter, then Jennifer is a doctor. For all x_12, if x_12 were an office clerk, then x_12 is a doctor. For all x_12, if x_12 drinks water, then x_12 is an office clerk. For all x_12, if x_12 were a doctor, then x_12 is an office clerk. For all x_12, if x_12 were an office clerk, then x_12 is drinking water. For all x_12, x_12 is not an office clerk.