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 y, if y climbs a mountain, then y is running. There is at least one y for which if y were a writer, then y is climbing a mountain. For all y, if y goes running, then y is a writer.
For all y, if y climbs a mountain, then y is a writer can be inferred via the universal transitivity rule. There is at least one y for which if y were a writer, then y is running can be inferred via the existential transitivity rule. There is at least one y for which if y goes running, then y is climbing a mountain can be inferred via the existential transitivity rule.