Elamur Groupantslatex-extract-dollars
The groupant beside latex/src/extract.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 |
signed_depth | signed_depth | partial source derived model | signed_depth |
paragraph | paragraph | partial source derived model | paragraph |
escape | escape | partial source derived model | escape |
arithmetic | arithmetic | partial source derived model | arithmetic |
Model text
descriptant
latex-extract-dollars
find_dollars skips escapes/comments to $$; find_dollar adds signed depth<=0 closer and LF blank-paragraph stop.
Epoch 2026-10-31: complete sources read before tests/model edits. Partial source-bound modeling; no production optimization or speed claim. Nested fragments share the parent lexical syntax. Caller/callee contracts outside owned files remain delegated.
approximant
Forward relation
find_dollars skips escapes/comments to $$; find_dollar adds signed depth<=0 closer and LF blank-paragraph stop.
Domain and executable surrogate gap
Bounded UTF-8 inputs and synthetic local files; supported parser-produced trees and representable arithmetic. Arbitrary public constructors are not certified total. Exact categorical semantics lack a useful percentage surrogate; no executable approximant attachment. Future numerical profiles require an explicit metric, zero case, source/evidence binding and supported 1/2/5/10% cap. Failure/effect differences cannot count as numerical error.
invariant
Invariant
For the scoped transition bytes [8019,9218): find_dollars skips escapes/comments to $$; find_dollar adds signed depth<=0 closer and LF blank-paragraph stop. Positive depth excludes inline close, not display close. Comments suppress contained dollars.
Cost
Linear byte scan, constant counter storage; i32 depth unchecked.
Allocation failure, stack exhaustion and unchecked counter overflow have no additional certificate. No timing claim or global error bound.
composition
Composition
find_dollars skips escapes/comments to $$; find_dollar adds signed depth<=0 closer and LF blank-paragraph stop.
For the scoped transition bytes [8019,9218): find_dollars skips escapes/comments to $$; find_dollar adds signed depth<=0 closer and LF blank-paragraph stop. Positive depth excludes inline close, not display close. Comments suppress contained dollars.
Parser, printer, AST equality, Macros, Rat and evaluator dependencies retain their own contracts. Structural roundtrip is not arithmetic definedness or numeric truth. Exact lexical binding does not prove caller/callee semantics.
models
behavior_complement
Positive depth excludes inline close, not display close. Comments suppress contained dollars.
reverse_reconstruction
Returned endpoint admits skipped escapes/comments but no earlier eligible closer; None includes paragraph stop or absent closer.
signed_depth
Unmatched } permits negative depth; actual condition<=0.
paragraph
LF then space/tab/CR then LF terminates.
escape
Backslash skips two bytes in ASCII-oriented scanner.
arithmetic
i32 depth unchecked; no all-size guarantee.
tests
Selected evidence
cargo test -p latex --features math --lib extract::tests
Two debug/two release executions retained matching sorted named outcomes. External wave28 latexbridge receipts retain numeric exits, compiled assertion controls, restoration, feature checks and source-test map. This scope is not exhaustive branch coverage; parent tests may only exercise some child transitions. Frozen VMM DATA/classification/hash subprocess, live corpus, teacher/API, training/GPU excluded. Reexport/feature compilation is separate from runtime semantics.
This page in Markdown → https://md.groupants.elamur.ai/free/en/mova/latex/src/extract.rs.groupant/dollars.groupant/