What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_13, x_13 will cook or x_13 will write a letter. For all x_13, if x_13 climbs a mountain, then x_13 is not a cashier. There is at least one x_13 for which x_13 will cook if and only if x_13 is a cashier. For all x_13, if x_13 writes a letter, then x_13 is a cashier.
There is at least one x_13 for which if x_13 cooks, then x_13 is a cashier. There is at least one x_13 for which if x_13 were a cashier, then x_13 is cooking.