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: For all x_17, if x_17 drinks water, then x_17 is driving a car. For all x_17, if x_17 were an electrician, then x_17 is drinking water. For all x_17, if x_17 drives a car, then x_17 is not writing a letter. There is at least one x_17 for which x_17 is not a nurse. For all x_17, x_17 is a nurse or x_17 will write a letter.
For all x_17, if x_17 were an electrician, then x_17 is driving a car can be inferred via the universal transitivity rule. There is at least one x_17 for which x_17 will write a letter can be inferred via the existential disjunctive syllogism rule.