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: Charles is a mechanic. For all x_25, if x_25 were a mechanic, then x_25 is reading a book. Barbara is running.
Charles is a mechanic and Barbara is running can be inferred via the conjunction rule. Barbara is running and Charles is a mechanic can be inferred via the conjunction rule. There is at least one x for which x is a mechanic can be inferred via the existential generalization rule.