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: If Charles listens to a song, then Mary is playing squash. Susan is a mechanic or Linda is cooking. If Susan were a mechanic, then Linda is a cashier. Mary is playing squash or Linda is not a cashier. For all x_22, if x_22 cooks, then x_22 is a cashier.
If Linda works, then Susan is a mechanic can be inferred via the rewriting rule. If Linda were a cashier, then Mary is playing squash can be inferred via the rewriting rule.