| R | Control.SessionTypes.Types, Control.SessionTypes |
| Rational | Control.SessionTypes.Indexed |
| Read | Control.SessionTypes.Indexed |
| read | Control.SessionTypes.Indexed |
| reader | Control.SessionTypes.Indexed |
| readFile | Control.SessionTypes.Indexed |
| readIO | Control.SessionTypes.Indexed |
| readList | Control.SessionTypes.Indexed |
| readLn | Control.SessionTypes.Indexed |
| readParen | Control.SessionTypes.Indexed |
| ReadS | Control.SessionTypes.Indexed |
| reads | Control.SessionTypes.Indexed |
| readsPrec | Control.SessionTypes.Indexed |
| Real | Control.SessionTypes.Indexed |
| RealFloat | Control.SessionTypes.Indexed |
| RealFrac | Control.SessionTypes.Indexed |
| realToFrac | Control.SessionTypes.Indexed |
| Rec | Control.SessionTypes.STTerm, Control.SessionTypes |
| recip | Control.SessionTypes.Indexed |
| recurse | Control.SessionTypes.MonadSession, Control.SessionTypes |
| recurse0 | Control.SessionTypes.MonadSession, Control.SessionTypes |
| recurseFix | Control.SessionTypes.MonadSession, Control.SessionTypes |
| Recv | Control.SessionTypes.STTerm, Control.SessionTypes |
| recv | Control.SessionTypes.MonadSession, Control.SessionTypes |
| Ref | Control.SessionTypes.Types, Control.SessionTypes |
| RefS | Control.SessionTypes.Types, Control.SessionTypes |
| RefZ | Control.SessionTypes.Types, Control.SessionTypes |
| rem | Control.SessionTypes.Indexed |
| RemoveRecv | Control.SessionTypes.Types, Control.SessionTypes |
| RemoveRecvST | Control.SessionTypes.Types, Control.SessionTypes |
| RemoveSend | Control.SessionTypes.Types, Control.SessionTypes |
| RemoveSendST | Control.SessionTypes.Types, Control.SessionTypes |
| rep | Control.SessionTypes.Codensity |
| repeat | Control.SessionTypes.Indexed |
| replicate | Control.SessionTypes.Indexed |
| Ret | Control.SessionTypes.STTerm, Control.SessionTypes |
| return | Control.SessionTypes.Indexed |
| reverse | Control.SessionTypes.Indexed |
| Right | |
| 1 (Data Constructor) | Control.SessionTypes.Indexed |
| 2 (Type/Class) | Control.SessionTypes.Types, Control.SessionTypes |
| round | Control.SessionTypes.Indexed |
| run | Control.SessionTypes.Debug |
| runAll | Control.SessionTypes.Debug |
| runAllM | Control.SessionTypes.Debug |
| runIxC | Control.SessionTypes.Codensity |
| runM | Control.SessionTypes.Debug |
| runSingle | Control.SessionTypes.Debug |
| runSingleM | Control.SessionTypes.Debug |