Index - O
| occ | Twee.Base |
| occurs | Twee.Term, Twee.Base |
| occursList | Twee.Term, Twee.Base |
| OneLineMode | Twee.Pretty, Twee.Base |
| optimise | Twee |
| Or | Twee.Constraints |
| order | Twee.Rule |
| Ordered | Twee.Constraints, Twee.Base |
| orElse | Twee.Utils |
| orient | Twee.Rule |
| Orientation | Twee.Rule |
| orientation | Twee.Rule |
| Oriented | Twee.Rule |
| oriented | Twee.Rule |
| orientTerms | Twee.Constraints, Twee.Base |
| overlap | Twee |
| overlaps | Twee |