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 doctor, then William is listening to a song. Robert is a doctor or William is a server. For all x_19, if x_19 were a server, then x_19 is listening to a song. It is cold or William is not listening to a song.
If William were a poet, then Robert is a doctor can be inferred via the rewriting rule. If William listens to a song, then it is cold can be inferred via the rewriting rule.