--- title: "modelcheck-syntax-node-coordinates — Mova code model" description: "Mova code model of tools/modelcheck/src/syntax.rs: components with their labels, obernants and the model text." url: "https://groupants.elamur.ai/free/en/mova/tools/modelcheck/src/syntax.rs.groupant/artifact-integrity.groupant/node-coordinates.groupant/" --- Elamur: [Mova](https://md.mova.elamur.ai/free/en/) · [Dictionary](https://md.dictionary.elamur.ai/free/en/) · [Research](https://md.research.elamur.ai/free/en/) · **Groupants** This page as HTML: # modelcheck-syntax-node-coordinates The groupant beside tools/modelcheck/src/syntax.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 - **kind:** groupant_fragment - **status:** partial - **source:** [`tools/modelcheck/src/syntax.rs`](https://github.com/ElamurAI/mova-free/blob/main/tools/modelcheck/src/syntax.rs) - **source SHA-256:** `35c315cc9b581bea…` - **covers:** Node coordinate and label admission (bytes 17620–18297) - **part of:** [modelcheck-syntax-artifact-integrity](https://md.groupants.elamur.ai/free/en/mova/tools/modelcheck/src/syntax.rs.groupant/artifact-integrity.groupant/) - **repository folder:** [`tools/modelcheck/src/syntax.rs.groupant/artifact-integrity.groupant/node-coordinates.groupant`](https://github.com/ElamurAI/mova-free/tree/main/tools/modelcheck/src/syntax.rs.groupant/artifact-integrity.groupant/node-coordinates.groupant) - **repository commit:** `855da7bd4a7b` > **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](#forward) | | **ast** | partial | `../../syntax.json` | | **cost** | partial | [Cost](#cost) | | **descriptant** | partial | [Descriptant](#descriptant) | | **invariant** | partial | [Invariant](#invariant) | | **tests** | partial | [Tests](#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 relational specification | [behavior_complement](#behavior-complement) | | `reverse_reconstruction` | reverse_reconstruction | partial relational specification | [reverse_reconstruction](#reverse-reconstruction) | | `empty_span_partition` | empty_span_partition | partial relational specification | [empty_span_partition](#empty-span-partition) | | `coordinate_width` | coordinate_width | partial relational specification | [coordinate_width](#coordinate-width) | | `label_opacity_projection` | label_opacity_projection | partial relational specification | [label_opacity_projection](#label-opacity-projection) | | `endpoint_failure_priority` | endpoint_failure_priority | partial relational specification | [endpoint_failure_priority](#endpoint-failure-priority) | ## Model text Subject: current manifest source SHA and exact UTF-8 range [17620,18297). The observation is one completed scoped call with adequate resources; source-derived relations are partial specifications. Filesystem checks describe sequential reads, not an atomic snapshot. ### Forward Convert unsigned start/end to usize; require ordered endpoints and a valid UTF-8 source slice; then require nonempty category/variant strings and Boolean opaque. Root/parent checks are later and separate. ### Invariant Zero-width syntax nodes are allowed, unlike nonempty fragment ranges. Endpoints inside a multibyte scalar reject. Labels need only be nonblank; category semantics remain unchecked. ### Cost Constant field access and endpoint checks per node plus label trimming; O(sum label bytes) over the projection. UTF-8 get checks bounds without rescanning the whole source slice. ### Descriptant Wave34, 2026-10-31: deeper scope retained under its existing parent without replacing historical views. Decode reuse was proposed before edits and checked against actual reference decoding; behavioral controls and repeated native receipts remain finite evidence. No numerical surrogate is justified for categorical validation outcomes; no percentage accuracy or complete semantic proof is claimed. ### Tests Exact native test: syntax::artifact_tests::declared_projection_rejects_stale_wrong_source_and_bad_ranges. Parent tests additionally exercise integration and failure order. Current evidence is in ../../wave34-evidence.md; old evidence remains explicitly historical in wave33-evidence.md at the source root. ### behavior_complement Exclude passage with negative/noninteger/unrepresentable offsets, start>end, offsets beyond text, split UTF-8 boundaries, blank category/variant or nonboolean opacity. Assurance: source-derived partial relation; fixed source revision and stated scope. Oracle: syntax::artifact_tests::declared_projection_rejects_stale_wrong_source_and_bad_ranges. Finite observations do not establish universal completeness. ### reverse_reconstruction Given admitted [a,b), compatible source texts have scalar boundaries at a and b and length at least b. Empty spans and arbitrary slice contents remain possible; admitted labels do not recover Rust syntax. Assurance: source-derived partial relation; fixed source revision and stated scope. Oracle: syntax::artifact_tests::declared_projection_rejects_stale_wrong_source_and_bad_ranges. Finite observations do not establish universal completeness. ### empty_span_partition start=end is admitted when the point is a UTF-8 boundary. This differs from fragment coverage a