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 Susan plays a game, then David is a nurse. If Richard works, then Susan is playing a game. If David were a nurse, then Richard is working.
If Susan plays a game, then Richard is working can be inferred via the transitivity rule. If Richard works, then David is a nurse can be inferred via the transitivity rule. If David were a nurse, then Susan is playing a game can be inferred via the transitivity rule.