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 takes a plane, then y is running. For all y, if y were an artist, then y is running. Charles is a poet. For all y, y is an artist or y will take a plane.
There is at least one x for which x is a poet can be inferred via the existential generalization rule. For all y, y will go running can be inferred via the universal disjunction elimination rule.