| o0 | Predicate.Util, Predicate |
| o2 | Predicate.Util, Predicate |
| o2n | Predicate.Util, Predicate |
| o3 | Predicate.Util, Predicate |
| oColor | Predicate.Util, Predicate |
| OctetRE | Predicate.Examples.Common |
| Odd | Predicate.Prelude, Predicate |
| ODebug | Predicate.Util, Predicate |
| oDebug | Predicate.Util, Predicate |
| oDisp | Predicate.Util, Predicate |
| Ok | Predicate.Examples.Refined3 |
| ok | Predicate.Examples.Refined3 |
| OkNot | Predicate.Examples.Refined3 |
| oknot | Predicate.Examples.Refined3 |
| OkNotR | Predicate.Examples.Refined3 |
| OkR | Predicate.Examples.Refined3 |
| ol | Predicate.Util, Predicate |
| olc | Predicate.Util, Predicate |
| OLite | Predicate.Util, Predicate |
| OneP | Predicate.Prelude, Predicate |
| Ones | Predicate.Prelude, Predicate |
| ONormal | Predicate.Util, Predicate |
| OrA | Predicate.Prelude, Predicate |
| OrdA | Predicate.Prelude, Predicate |
| OrdA' | Predicate.Prelude, Predicate |
| OrderingP | Predicate.Util, Predicate |
| OrdI | Predicate.Prelude, Predicate |
| OrdP | Predicate.Prelude, Predicate |
| Ors | Predicate.Prelude, Predicate |
| OrT | Predicate.Util, Predicate |
| OSubNormal | Predicate.Util, Predicate |
| ou | Predicate.Util, Predicate |
| ou3 | Predicate.Util, Predicate |
| oun | Predicate.Util, Predicate |
| OVerbose | Predicate.Util, Predicate |
| oWidth | Predicate.Util, Predicate |
| oz | Predicate.Util, Predicate |
| OZero | Predicate.Util, Predicate |