What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: There is at least one x_6 for which if x_6 makes tea, then x_6 is not a sailor. For all x_6, x_6 will play squash. For all x_6, x_6 is a cashier. For all x_6, if x_6 plays squash, then x_6 is a sailor.
For all x_6, x_6 is a sailor can be inferred via the universal modus ponens rule. For all x_6, x_6 will play squash and x_6 is a cashier can be inferred via the universal conjunction rule. For all x_6, x_6 is a cashier and x_6 will play squash can be inferred via the universal conjunction rule.