| epochReduction | Object | true | https://uor.foundation/stream/Epoch | https://uor.foundation/reduction/EulerReduction | The reduction execution for this epoch. |
| epochOutput | Object | true | https://uor.foundation/stream/Epoch | https://uor.foundation/schema/Datum | The output datum produced by this epoch. |
| epochContext | Object | true | https://uor.foundation/stream/Epoch | https://uor.foundation/state/Context | The context at the start of this epoch. |
| boundaryFrom | Object | true | https://uor.foundation/stream/EpochBoundary | https://uor.foundation/stream/Epoch | The epoch that just completed. |
| boundaryTo | Object | true | https://uor.foundation/stream/EpochBoundary | https://uor.foundation/stream/Epoch | The epoch about to begin. |
| continuationContext | Object | true | https://uor.foundation/stream/EpochBoundary | https://uor.foundation/state/Context | The context carried across the boundary. |
| prefixEpochs | Object | false | https://uor.foundation/stream/StreamPrefix | https://uor.foundation/stream/Epoch | The epochs in this prefix (ordered by stream:epochIndex). |
| unfoldSeed | Object | true | https://uor.foundation/stream/Unfold | https://uor.foundation/state/Context | The initial context for the stream. |
| unfoldStep | Object | true | https://uor.foundation/stream/Unfold | https://uor.foundation/morphism/ComputationDatum | The certified step function producing each epoch. |
| unfoldResult | Object | true | https://uor.foundation/stream/Unfold | https://uor.foundation/stream/ProductiveStream | The stream produced by this unfold. |
| epochIndex | Datatype | true | https://uor.foundation/stream/Epoch | http://www.w3.org/2001/XMLSchema#nonNegativeInteger | Zero-based index of this epoch in the stream. |
| prefixLength | Datatype | true | https://uor.foundation/stream/StreamPrefix | http://www.w3.org/2001/XMLSchema#positiveInteger | Number of epochs in this prefix. |
| isProductive | Datatype | true | https://uor.foundation/stream/ProductiveStream | http://www.w3.org/2001/XMLSchema#boolean | Always true by construction: every epoch terminates. Invariant, not computed. |
| stepTerm | Object | true | https://uor.foundation/stream/ProductiveStream | https://uor.foundation/schema/Term | A term denoting a function from the current seed value to a pair (head, next_seed). |
| productivityWitness | Datatype | true | https://uor.foundation/stream/ProductiveStream | http://www.w3.org/2001/XMLSchema#string | IRI of a proof of stream productivity (coinductive well-foundedness). |