| SC | Zsyntax.Labelled.Rule.Interface, Zsyntax.Labelled.Rule |
| SchemaLCtxt | Zsyntax.Labelled.Rule.Interface, Zsyntax.Labelled.Rule |
| search | |
| 1 (Function) | Otter.Internal.Search, Otter |
| 2 (Function) | Zsyntax |
| searchLabelled | Zsyntax |
| SearchNode | Otter.Internal.Structures |
| SearchProperRule | Otter.Internal.Structures |
| SearchRes | Otter.SearchRes, Otter, Zsyntax |
| SearchRule | Otter.Internal.Structures |
| Sequent | Zsyntax.Formula, Zsyntax |
| SLC | Zsyntax.Labelled.Rule.Interface, Zsyntax.Labelled.Rule |
| SpaceTooBig | Otter.SearchRes, Otter, Zsyntax |
| SQ | Zsyntax.Formula, Zsyntax |
| SSchema | Zsyntax.Labelled.Rule.Interface, Zsyntax.Labelled.Rule |
| SSEmptyGoal | Zsyntax.Labelled.Rule.Interface, Zsyntax.Labelled.Rule |
| SSFullGoal | Zsyntax.Labelled.Rule.Interface, Zsyntax.Labelled.Rule |
| Stage | Otter.Internal.Structures |
| SubCtxt | Zsyntax.Labelled.Rule.Interface, Zsyntax.Labelled.Rule |
| subCtxtOf | Zsyntax.Labelled.Rule.Interface, Zsyntax.Labelled.Rule |
| Subsumable | Otter.Internal.Structures, Otter |
| subsumes | Otter.Internal.Structures, Otter |
| SupersetClosed | Zsyntax.ReactionList |
| switchN | Zsyntax.Labelled.Rule.Interface, Zsyntax.Labelled.Rule |