Elamur Groupantsworld-store-carry
The groupant beside world/src/store.rs in the Mova repository: what the code computes, what it never does, how to go back from its outputs, its invariants, cost and checks.
Facts
Implementation material. A Mova code model describes this code at one source revision: partial models, finite checks and their stated scope. It is not a reviewed general exposition, and its labels are shown as written, never raised.
Components
| component | label | where |
|---|---|---|
| approximant | partial | Forward |
| ast | partial | ../../syntax.json |
| cost | symbolic unmeasured | Cost |
| descriptant | present | model.md |
| invariant | partial | Invariant |
| tests | bounded evidence | ../../model.md#tests |
Obernants
The typed relations around the forward model: the behaviour complement (what the code never does), the reverse reconstruction (every input compatible with an output) and specialised views.
| id | type | label | where |
|---|---|---|---|
nonbehavior | behavior_complement | partial source derived model | nonbehavior |
antecedents | reverse_reconstruction | partial source derived model | antecedents |
carry-equivalence | membership_transfer | partial source derived model | carry-equivalence |
invalidation | policy_partition | partial source derived model | invalidation |
cost | resource_preimage | partial source derived model | cost (catalog) |
Model text
descriptant
carry
Forward
Order stamps check key/base; ordinary stable/current stamps return saved parsed rows. Stale sampled/prefix queries recompute once, persist and return that vector. Remaining ancestor queries merge O outside C with F inside C; unrelated versions recompute.
Invariant
Successful recomputation persists and returns one selected vector. Pointwise carry equals full selection iff O outside C equals F outside C. Stable stamps remain trusted even with manually incompatible queries.
Cost
Full selection plus serialization on recompute. Ancestor carry also performs full selection and dictionary reads. Changed-ID count does not count evaluated candidates.
Epoch memory
2026-10-29: The baseline witness returned [] versus full [2]. The repaired regression requires [2]. Finite algebra checks the merge relation and its converse/complement; it does not certify feature extraction.
catalog
world-store-carry
Source SHA-256 6801677c4f17273e615090a790f2e4018387ca5d006aab899bafda09f01b24d9. Conditional models over successful finite operations; I/O failure, malformed offsets and changing dependency state are excluded unless stated. Algebra is exact only for its declared abstract relation. Source correspondence remains bounded.
nonbehavior
Type: behavior_complement.
Universe: valid acyclic stores, successful calls, valid query and saved-stamp state paired with returned IDs and rewritten bytes. Candidate inner complement: a stale sampled tree set taking the ancestor delta-merge branch; a current or stable non-order stamp rewriting on load; an order stamp ignoring a changed key. These exclusions depend on branch priority, not merely the final vector. Oracle: repaired witness, stamp fixtures and source branch inspection.
antecedents
Type: reverse_reconstruction.
Fix query, target version and filesystem dependencies. The preimage of returned Y is the union of admitted saved files over all stamp branches: current/stable parsed rows equal Y; invalidated sampling/order/unrelated branches have select(target)=Y; pointwise ancestor branch satisfies O minus C = Y minus C and F intersect C = Y intersect C. Values O intersect C are unconstrained. Branch evidence cannot be recovered from IDs alone; saved bytes and writes refine this fiber.
carry-equivalence
Type: membership_transfer.
For sets O,F,C, M=(O\C) union (F intersect C). Exactly M=F iff O\C=F\C. SampleCarry.lean proves this for arbitrary sets, equivalently symmetric difference of O and F is contained in C, and proves the complete compatible-predecessor relation. Its independent false universal equality control fails. This is an abstract proof, not verified Rust correspondence. Exhaustive finite oracle enumerates every triple over four IDs and every candidate output; it checks equality, complement and reverse fibers. This algebra is exact for the merge operator, not a proof that production dictionaries cover all relevant feature deltas.
invalidation
Type: policy_partition.
Priority is order-stamp handling, then stable/current shortcut, then stale sampled/prefix recomputation, then ancestor discovery and pointwise merge or unrelated recomputation. Recompute discards old membership, including duplicates and stale omissions. A stable stamp is trusted even if manually paired with a tree query; malformed saved-state authentication is outside this repair. Exact source and fixture checks bind the policy.
cost (catalog)
Type: resource_preimage.
Recompute selects once, then persists and returns that same vector. For stale sampled queries full selection costs O(n log n) ranking per sample term; it avoids ancestor dictionary scanning. Bounded calibration is recorded separately in current-evidence.md; it does not establish a general speedup. Pointwise ancestor carry still computes full selection then restricts merge to changed IDs. Refreshed prefix stamps use the shared recompute path. Cache, I/O and repeated sampling terms are held explicit.
This page in Markdown → https://md.groupants.elamur.ai/free/en/mova/world/src/store.rs.groupant/selection.groupant/carry.groupant/