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, x_11 will drink water if and only if x_11 is a cashier. For all x_11, if x_11 were a cashier, then x_11 is not writing a letter. There is at least one x_11 for which x_11 will write a letter.
There is at least one x_11 for which x_11 is not a cashier. For all x_11, if x_11 drinks water, then x_11 is a cashier. For all x_11, if x_11 were a cashier, then x_11 is drinking water.