WIP: feat: mechanization of "Interval Tree Clocks" - #17
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This PR introduces a simplified version of "Interval Tree Clocks", described by Almeida et al. in their similarly named paper. Note: we just introduce the tree-based definitions, and prove they have the desired properties directly, without defining the denotation of such trees into actual intervals/sets. We also simplify the model a lot, by removing arbitrary events, and instead saying that a merge also counts as an event. By doing so, we can replace the event-tree by a single natural number, making it much simpler to reason about. We do use the id-tree exactly as defined in the paper, but since we eliminated the tree structure from the event component, we had to come up with a novel definition of the happens-before relation. This gives us a clock with a fork and join operations. This PR also proves that the arguments to these operations always happen before their results. Desired properties around independence are stated, but not yet proven. WIP because I had to last-minute tweak the happens-before relation, and should still check that the new definition (a) actually is the correct one, and (b) is consistent with the documentation.
These are not super important; they ought to hold but I don't expect we'll actually have to invoke them, so I'll ignore them for now
The blow up got fixed now that sink_sink is gone
alexkeizer
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alexkeizer
marked this pull request as draft
March 12, 2026 13:13
This was referenced Mar 12, 2026
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This PR introduces a mechanization of "Interval Tree Clocks", described by Almeida et al. in their similarly named paper.
We also simplify the model a bit, by removing arbitrary events, and instead saying that a split also counts as an event.
This gives us a clock with a fork and join operations. This PR also proves that the arguments to these operations always happen before their results. Desired properties around independence are stated, but not yet proven.
This PR subsumes #13
Currently work-in-progress: the definitions exist, but the relevant properties still have to be proven.