Index - O
| odd | Prelude.Compat |
| on | Data.Function.Compat |
| onException | Control.Exception.Compat |
| OptArg | System.Console.GetOpt.Compat |
| OptDescr | System.Console.GetOpt.Compat |
| Option | System.Console.GetOpt.Compat |
| optional | Control.Applicative.Compat |
| or | |
| 1 (Function) | Data.Foldable.Compat, Prelude.Compat |
| 2 (Function) | Data.List.Compat |
| Ord | Data.Ord.Compat, Prelude.Compat |
| Ordering | Data.Ord.Compat, Prelude.Compat |
| otherwise | Data.Bool.Compat, Prelude.Compat |
| Overflow | Control.Exception.Compat |