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_19, x_19 will go running or x_19 will play squash. There is at least one x_19 for which x_19 will play squash if and only if x_19 will drive a car. For all x_19, x_19 will climb a mountain. For all x_19, x_19 will not drive a car. For all x_19, x_19 will not go running or x_19 is a writer.
For all x_19, x_19 will play squash or x_19 is a writer can be inferred via the universal resolution rule. There is at least one x_19 for which if x_19 plays squash, then x_19 is driving a car can be inferred via the existential biconditional elimination rule. There is at least one x_19 for which if x_19 drives a car, then x_19 is playing squash can be inferred via the existential biconditional elimination rule. There is at least one x_19 for which x_19 will not play squash can be inferred via the existential biconditional elimination rule.