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: Robert is sad or it is cloudy. If Robert were an artist, then James is a server. If it is overcast, then John is playing tennis. If Robert were sad, then Robert is an artist. If it is cloudy, then it is overcast. If James were a server, then John is playing tennis.
If Robert were an artist, then John is playing tennis can be inferred via the transitivity rule. If Robert were sad, then James is a server can be inferred via the transitivity rule. If it is cloudy, then John is playing tennis can be inferred via the transitivity rule.