# window exit versus removed part (distinction)

That a thing can end when a parameter crosses a wall, as distinguished from ending when a part is taken away. The test is whether maintenance can keep the thing inside its window while parts are removed.

- Computed level: L15 (depth in the emergence graph, not abstraction)
- Status: review  ·  Domain: ontology  ·  Arena: emergence

## Emergence
**Emerges from:** [window](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-window.range), [wall](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-wall.range-end), [parameter](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-parameter.condition), [maintenance](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-maintenance.upkeep), [part](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-part.relation), [cross](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-cross.symbol), [take](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-take.acquisition), [test](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-test.assessment), [whether](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-whether.conditional), [inside](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-inside.spatial), [change](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-change.process), [time](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-time.dimension)

**Through:** These components together distinguish two modes of ending: one by crossing a boundary in a condition, the other by removal of a piece, tested by whether upkeep can preserve the whole despite such removals.

**Novel properties:**
- distinction between crossing and removal as causes of ending
- role of maintenance in sustaining existence within limits
- testable difference between persistence conditions

## Examples
- The International Space Station maintains orbit through periodic reboosts, despite losing modules over decades. *(engineering)*
- A star remains a main-sequence star as long as core fusion continues, even as it loses mass via solar wind. *(astrophysics)*
- The U.S. Senate retained legislative function after Alaska and Hawaii joined, expanding the union without structural loss. *(institutions)*

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*Canonical: https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-window-exit-versus-removed-part.distinction*  
*Structured data: https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-window-exit-versus-removed-part.distinction.json*  
*Every definition provably resolves to space, time, energy and pattern.*