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 were a cashier, then x_6 is sad. For all x_6, x_6 will play tennis or x_6 will play a game. For all x_6, x_6 will not play tennis. For all x_6, if x_6 plays a game, then x_6 is a cashier.
There is at least one x_6 for which if x_6 plays a game, then x_6 is sad can be inferred via the existential transitivity rule. For all x_6, x_6 will play a game can be inferred via the universal disjunctive syllogism rule.