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: If Susan plays squash, then William is driving a car. For all x_17, if x_17 makes tea, then x_17 is playing squash. If William drives a car, then Susan is making tea. Susan is playing squash.
If Susan plays squash, then Susan is making tea can be inferred via the transitivity rule. There is at least one x for which x will play squash can be inferred via the existential generalization rule.