Elamur Groupantsworld-schoolbench-selection
The groupant beside world/src/schoolbench.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 source model | forward |
| ast | partial | ../syntax.json |
| composition | partial source model | composition |
| cost | partial source model | cost |
| descriptant | partial source model | epoch-memory |
| invariant | partial source model | invariant |
| tests | partial source model | checks |
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 |
|---|---|---|---|
world-schoolbench-selection-behavior-complement | behavior_complement | partial source model | behavior-complement |
world-schoolbench-selection-reverse-reconstruction | reverse_reconstruction | partial source model | reverse-reconstruction |
world-schoolbench-selection-rank-oracle | constraint_relation | partial source model | rank-oracle |
world-schoolbench-selection-nested-subsets | order_relation | partial source model | nested-subsets |
Model text
Source-bound epoch 2026-10-30. Every view below uses this exact source revision and finite inputs with sufficient allocation resources. Forward/absent/reverse relations observe only the stated projection; filesystem models assume fixed supplied dependencies and distinguish successful returns from partial effects. Status: partial source model, with bounded native evidence in evidence.md at the root sidecar. No approximation percentage, universal proof or school accuracy claim.
forward
Partition by stars, compute stable digest from seed/course/n, lexically sort digest-index pairs, take ceil(n_s/d), sort global indices.
invariant
Per nonempty stratum select at least one and at most n_s; Full selects every original index exactly once, even duplicate identities.
cost
O(N identity bytes + sum n_s log n_s + K log K), O(N) stored pairs; hashes compared as strings.
composition
Leaf projections share exact lesson identities, selected indices, text bytes and option ordering. Compose only with those shared values retained; isolated score/length observations cannot recover them. Source inspection identifies knowledge::main_args dispatch, schoolbench selected-lessons -> counts -> run_course_lessons -> trace scoring, and schooltools option_line -> canon -> tally/lint/edit. Tests execute native pure helpers and isolated snapshot/restore; no live course/parser/teacher call.
epoch-memory
Initial coverage records tolerant parser/score semantics and per-file effect boundaries. Model review exposed the direct zero restore index panic, repaired after old-code failure. Benchmark score loop was extracted unchanged to a pure private helper to test actual classification and width/count gates. Lock constructor failure may leave a stale directory; argument failures can consume flags. These remain explicit source-inspected limitations.
checks
Native module filters schoolbench:: and schooltools::, including eight new wave9 tests; independent finite rank/cadence/length/fraction oracles and a restore no-effect fixture. Raw evidence is external under $MOVA_DATA/runs/octopus-wave9-school-2026-10-30; root evidence.md binds outcomes. Macro bodies in syntax projection remain opaque; finite agreement does not certify unbounded input space.
behavior-complement
Type: behavior_complement. Subject: world-schoolbench-selection, epoch 2026-10-30. Domain and observation: scoped inputs and projected outputs defined here. Operator/assumptions: For fixed inputs, inner absent results include reordered output, omissions in full, and selections violating per-stratum quota or rank. No assertion that different seeds necessarily yield different subsets. Evidence/status: source-inspected relation with the bounded tests named under checks; unenumerated behavior remains unknown. Complement claims are inner constraints, reverse claims retain all compatible candidates rather than identifying a historical cause.
reverse-reconstruction
Type: reverse_reconstruction. Subject: world-schoolbench-selection, epoch 2026-10-30. Domain and observation: scoped inputs and projected outputs defined here. Operator/assumptions: Selected indices constrain only quota and winning ranks. Any replacement lesson facts/questions with unchanged course/n/stars is compatible; rank ties preserve original indices. Hash preimage reconstruction is not implemented. Evidence/status: source-inspected relation with the bounded tests named under checks; unenumerated behavior remains unknown. Complement claims are inner constraints, reverse claims retain all compatible candidates rather than identifying a historical cause.
rank-oracle
Type: constraint_relation. Subject: world-schoolbench-selection, epoch 2026-10-30. Domain and observation: scoped inputs and projected outputs defined here. Operator/assumptions: Independent bounded oracle counts peers with smaller (digest,index) and includes i iff rank*d < stratum-size; 49 lengths times three seeds times three tiers =441 comparisons. It shares the digest primitive, so hash correctness is external. Evidence/status: source-inspected relation with the bounded tests named under checks; unenumerated behavior remains unknown. Complement claims are inner constraints, reverse claims retain all compatible candidates rather than identifying a historical cause.
nested-subsets
Type: order_relation. Subject: world-schoolbench-selection, epoch 2026-10-30. Domain and observation: scoped inputs and projected outputs defined here. Operator/assumptions: For same strata/ranks, ceil(n/8)<=ceil(n/3)<=n; prefixes compose into subset inclusion after chronological sorting. Changing lessons, stars or seed voids this premise. Evidence/status: source-inspected relation with the bounded tests named under checks; unenumerated behavior remains unknown. Complement claims are inner constraints, reverse claims retain all compatible candidates rather than identifying a historical cause.
This page in Markdown → https://md.groupants.elamur.ai/free/en/mova/world/src/schoolbench.rs.groupant/selection.groupant/