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 Michael were poor, then James is happy. If it is overcast, then Michael is poor. It is overcast or John is cooking. If Patricia were a writer, then James is not happy. Michael is playing tennis. If John cooks, then James is happy.
If it is overcast, then James is happy can be inferred via the transitivity rule.