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 Jessica were a scientist, then Robert is an astronaut. If it is cold, then it is overcast. Jessica is a scientist or Richard is not excited. If Robert were an astronaut, then it is cold.
If Jessica were a scientist, then it is cold can be inferred via the transitivity rule. If Robert were an astronaut, then it is overcast can be inferred via the transitivity rule. If Richard were excited, then Jessica is a scientist can be inferred via the rewriting rule.