Elamur Groupantscoref-mention
The groupant beside coref/src/mention.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 | approximant |
| ast | partial | syntax.json |
| composition | partial | composition |
| descriptant | present | descriptant |
| invariant | partial | invariant |
| tests | executed bounded checks | 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 |
|---|---|---|---|
behavior_complement | behavior_complement | partial source derived model | behavior_complement |
reverse_reconstruction | reverse_reconstruction | partial source derived model | reverse_reconstruction |
feature_precedence | feature_precedence | partial source derived model | feature_precedence |
coordination | coordination | partial source derived model | coordination |
span_geometry | span_geometry | partial source derived model | span_geometry |
modifier_transport | modifier_transport | partial source derived model | modifier_transport |
Parts
Model text
descriptant
coref-mention
Extract ordered nominal mentions and linguistic feature masks from valid document trees without reading Entity.
State: Valid acyclic Document, COREF_MD snapshot, nominal head candidates and retained feature/text projections.
Epoch 2026-10-31: prospective analysis preceded test additions. Production behavior is unchanged. A registry entry records partial source-bound modeling, not verification.
No exhaustive closed-list validation or malformed/cyclic public documents; production rule accuracy is unmeasured.
approximant
Forward model
is_head applies UPOS/role exclusions and optional idiom/compound switches. span_of traverses the head's allowed children then descendants; take first/last nonpunctuation/symbol and retain matching edge brackets. Coordination may emit full group and own span. build chooses pronoun table then ordered FEATS overrides, with number FEATS only when table number unknown; nonpronoun coordination forces PL and titles OR gender. Sort (sent,start,-end,head), dedup equal spans.
Domain: acyclic, in-range document views from checked parsing unless explicitly discussing permissive adapters; stable environment during each call; finite addressable allocations. Public vectors can be malformed and panic.
No runtime substitute or numerical error budget is established.
invariant
Invariant and cost
Each detected valid-domain mention contains its head and has unique span after dedup; coordination and own spans may share head. Mask0 means unknown, not negation. Relative/interrogative are internal. No name-based gender inference and no gold lookup. Bounds are interval hulls and can contain unrelated tokens.
Conservative O(sum nĀ³ + M log M + emitted text bytes): each head can traverse closure and each modifier can walk n ancestors; retained mention strings/features can be O(NĀ²) bytes. Recursive graph walks use explicit stacks but require acyclicity; no dimension cap.
Integer counters/lengths use Rust native arithmetic with no separate overflow certificate. Allocation exhaustion, panics and I/O failures are not experimentally characterized.
composition
Source-fragment composition
Fragments project exact byte ranges of this source; shared types/imports outside ranges remain prerequisites. Models compose through actual caller/callee state, not an error-budget sum.
- heads: bytes [7940,13544); Environment-driven eligibility and nominal-span closure.
- features: bytes [13544,21753); Lexical/FEATS projection, modifier locality and mask precedence.
- detection: bytes [21753,23334); Event constructor and sorted/deduplicated nominal/coordination emission.
Parent relation: is_head applies UPOS/role exclusions and optional idiom/compound switches. span_of traverses the head's allowed children then descendants; take first/last nonpunctuation/symbol and retain matching edge brackets. Coordination may emit full group and own span. build chooses pronoun table then ordered FEATS overrides, with number FEATS only when table number unknown; nonpronoun coordination forces PL and titles OR gender. Sort (sent,start,-end,head), dedup equal spans.
Integration: checked document tree -> mention spans/features -> ordered resolver partition -> eval visibility -> CorefUD rows or existing score module. Source-specific exceptions and projection losses remain in models.md.
models
Typed models
behavior_complement
At default settings an expl pronoun, flat nominal child, title or excluded idiom cannot become an independent detected head. Output excludes duplicate spans, but not overlap or duplicate heads. Event helper creates Kind::Other SG/INAN and does not require ordinary nominal-head eligibility.
reverse_reconstruction
For mention vector V, compatible inputs are all documents/environment snapshots yielding V after projection and span dedup; ignored Entity, unrelated comments and some syntax/FEATS can vary. Text lowercasing and removed title information prevent unique source reconstruction.
feature_precedence
Pron type: Reflex > Rel > Int/IntRel > Dem > Ind/Tot/Neg > Rcp > Poss. Person1 > Person2 > Person3 overrides table. Known pronoun number is not overwritten by contradictory Number FEATS.
coordination
For a nominal conjunct child, own span cuts direct conj/cc children; full span emitted only if different. Full group number PL; dedup by span after sort may discard a different head.
span_geometry
Head-level cuts do not recur for lower descendants. Hull includes intervening positions; bracket edge retention requires an inside matching mate, not a general balanced-parentheses proof.
modifier_transport
words retains content POS except titles; mods/proper_mods exclude flat name and paths through subordinate/appos/conj edges. head_key is last flat-name word, unlike head_low used by strict head sieves.
No executable percentage surrogate: categorical state/effect semantics currently lack a useful cheaper observation metric. Supported future caps are 1%, 2%, 5%, 10%; no profile is claimed here.
tests
Evidence ā 2026-10-31
Safe synthetic command: env -u COREF_X -u COREF_MD -u PRAG_OFF cargo test -p coref tests:: -- --skip score::. Two debug and two release executions are retained externally with numeric exit status and sorted named outcomes. Selected checks:
- tests::story_chains_and_reasons
- tests::wave27_coordination_mentions_and_visibility
See source-test-map.json and controls.json in the wave27 coref run receipts. The library declaration file has compilation evidence only. No corpus, teacher, GPU or speed measurement.
Partial scope: No exhaustive closed-list validation or malformed/cyclic public documents; production rule accuracy is unmeasured.
Measured receipts
Final source state: 13 named tests (12 library, 1 binary) passed twice debug and twice release, 52 total executed test instances; all four command exits0 and sorted named outcomes identical. Five added tests are four library boundary tests plus one main load test. The pre-existing score tests and groupant_transfers were filtered out.
Compiled actual-source control: tests::wave27_coordination_mentions_and_visibility. Compile exit0, assertion-run exit101, exact bytes restored, positive rerun exit0. Retained logs: control-mention-compile.log, control-mention-red.log, control-mention-restored.log.
Nine source AST projections were generated twice identically. Shared ancestor declarations are deferred to root integration; local owned leaves have no structural diagnostics. No timings or general accuracy claim.
Strict scoped Clippy: exit101 on four pre-existing production lints (corefud unnecessary_sort_by, doc if_same_then_else and clone_on_copy, mention collapsible_if). Those source files are byte-identical to the base. No unrelated lint refactor was made.
This page in Markdown ā https://md.groupants.elamur.ai/free/en/mova/coref/src/mention.rs.groupant/