Index - O
| odd | Prologue.Data.Num, Prologue |
| on | Prologue |
| oneShot | Prologue.Prim, Prologue |
| OneTuple | |
| 1 (Type/Class) | Prologue.Data.OneTuple, Prologue.Data.Tuple, Prologue |
| 2 (Data Constructor) | Prologue.Data.OneTuple, Prologue.Data.Tuple, Prologue |
| optional | Prologue |
| or | Prologue.Data.Foldable, Prologue |
| or# | Prologue.Prim |
| Ord | Prologue.Data.Basic, Prologue |
| ord# | Prologue.Prim |
| Ord1 | Prologue |
| Ordering | Prologue.Data.Basic, Prologue |
| orI# | Prologue.Prim |
| otherwise | Prologue.Data.Basic, Prologue |
| over | Prologue |