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_1, if x_1 were a poet, then x_1 is taking a plane. For all x_1, if x_1 plays tennis, then x_1 is a poet. There is at least one x_1 for which if x_1 takes a plane, then x_1 is playing tennis.
For all x_1, if x_1 plays tennis, then x_1 is taking a plane can be inferred via the universal transitivity rule. There is at least one x_1 for which if x_1 takes a plane, then x_1 is a poet can be inferred via the existential transitivity rule. There is at least one x_1 for which if x_1 were a poet, then x_1 is playing tennis can be inferred via the existential transitivity rule.