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 Robert were a writer, then Joseph is fast. If Robert listens to a song, then James is sad. If it is sunny, then Robert is listening to a song. If James were sad, then Robert is a writer.
If Robert listens to a song, then Robert is a writer can be inferred via the transitivity rule. If it is sunny, then James is sad can be inferred via the transitivity rule. If James were sad, then Joseph is fast can be inferred via the transitivity rule.