Elamur Groupantswasi-mlab-gate
The groupant beside wasi-host/examples/mlab_gate.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 |
| cost | symbolic source derived | invariant |
| descriptant | present | descriptant |
| invariant | partial | invariant |
| tests | compile and source review | 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 |
argument_selection | argument_selection | partial source derived model | argument_selection |
external_reference | external_reference | partial source derived model | external_reference |
comparison_projection | comparison_projection | partial source derived model | comparison_projection |
empty_suite | empty_suite | partial source derived model | empty_suite |
Parts
Model text
descriptant
wasi-mlab-gate
Example reads fixed mlab.wasm, constructs Host then for each .txt path parses scenarios; each runs native capture with fresh Vfs and guest with fresh Vfs/merged stderr, appends textual trap, compares output strings, accumulates wall times and divergence list. Main not executed in wave31.
Epoch 2026-10-31
Prospective review recorded before edits. Source review found late output FAULT effects and weaker-than-capability rights metadata; these are modeled as current behavior rather than silently repaired. Only bounded new test blocks were added; production code remains unchanged. Actual finite results and exact restoration receipts live under $MOVA_DATA/runs/octopus-wave31-wasi-2026-10-31. No full mlab guest, frozen suite, GPU or corpus run. This node retains its scoped observations for future refinement.
approximant
Forward relation
Example reads fixed mlab.wasm, constructs Host then for each .txt path parses scenarios; each runs native capture with fresh Vfs and guest with fresh Vfs/merged stderr, appends textual trap, compares output strings, accumulates wall times and divergence list. Main not executed in wave31.
Scope: wasi-mlab-gate. State and transitions follow the authoritative source, including partial effects before errors. No executable approximate replacement is attached: categorical errno/effects and module execution lack a useful validated percentage metric; future numerical profiles may only use1/2/5/10% caps after domain/reference evidence.
invariant
Invariant and cost
Example reads fixed mlab.wasm, constructs Host then for each .txt path parses scenarios; each runs native capture with fresh Vfs and guest with fresh Vfs/merged stderr, appends textual trap, compares output strings, accumulates wall times and divergence list. Main not executed in wave31.
The invariant is conditional on the admitted transition: With no differences and successful traversal, final status1 is excluded; matching output does not exclude nonzero guest exit or different Vfs.
Cost: O(suite bytes+outputs+diff text)+sum native and guest run costs, unbounded scenario workload. No measured speed ratio.
No wall-time gain, universal resource bound or atomic rollback is inferred. External Vfs/wasmi/native-mlab work remains separately charged.
composition
Composition
Example reads fixed mlab.wasm, constructs Host then for each .txt path parses scenarios; each runs native capture with fresh Vfs and guest with fresh Vfs/merged stderr, appends textual trap, compares output strings, accumulates wall times and divergence list. Main not executed in wave31.
Immediate fragments partition selected mechanisms; their byte ranges refer to this single source and reuse its syntax projection. Memory helper success is a precondition for ABI transport, not proof that all linker wrappers dispatch correctly. WASI path/read/write helpers call real Vfs; mlab remains an external reference. Remaining top-level definitions and test bodies stay covered only by the parent source model.
models
Typed model catalog
behavior_complement
Subject: wasi-host/examples/mlab_gate.rs at SHA-256 a7947069ab507ffd5ad7b71ae9146bca16e08b827af78bc5961993c788b699b8, scope wasi-mlab-gate. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: With no differences and successful traversal, final status1 is excluded; matching output does not exclude nonzero guest exit or different Vfs.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
reverse_reconstruction
Subject: wasi-host/examples/mlab_gate.rs at SHA-256 a7947069ab507ffd5ad7b71ae9146bca16e08b827af78bc5961993c788b699b8, scope wasi-mlab-gate. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: same/total and summed times admit arbitrarily many code/output histories; output equality does not recover state equivalence or successful nonzero-exit status.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
argument_selection
Subject: wasi-host/examples/mlab_gate.rs at SHA-256 a7947069ab507ffd5ad7b71ae9146bca16e08b827af78bc5961993c788b699b8, scope wasi-mlab-gate. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: vm enabled by any --vm, fuel uses first --fuel next value parse; only args ending .txt are suite paths.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
external_reference
Subject: wasi-host/examples/mlab_gate.rs at SHA-256 a7947069ab507ffd5ad7b71ae9146bca16e08b827af78bc5961993c788b699b8, scope wasi-mlab-gate. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: mlab Interp and suite parser are external references, not owned runtime implementation; native/guest equality is a gate hypothesis.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
comparison_projection
Subject: wasi-host/examples/mlab_gate.rs at SHA-256 a7947069ab507ffd5ad7b71ae9146bca16e08b827af78bc5961993c788b699b8, scope wasi-mlab-gate. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: Guest stdout decoded lossily and concatenated trap; nonzero proc_exit without trap may compare equal because exit_code is ignored.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
empty_suite
Subject: wasi-host/examples/mlab_gate.rs at SHA-256 a7947069ab507ffd5ad7b71ae9146bca16e08b827af78bc5961993c788b699b8, scope wasi-mlab-gate. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: Even zero selected txt files still reads/builds Host; afterward0/0 and exit0 if no differences.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
tests
Checks and limits
Source review and compilation only for this scope; no runtime branch-coverage claim.
Exact names: .
Memory tests bypass linker ABI; tiny empty/unreachable guests exercise engine outcomes only. The CLI test uses isolated import/export/journal fixtures.
Five compiled production/helper-source controls: append offset, virtual clock advance, trap status, CLI export gate and newest-mtime max. Each compiles, fails its selected assertion, restores exact original bytes and passes again. These controls cover their target relations, not every node. No assertion-only mutants. See external source-test-map.json, native-commands.json, verify.rs and numeric/raw receipts in $MOVA_DATA/runs/octopus-wave31-wasi-2026-10-31. The example main and frozen mlab paths are never executed.
This page in Markdown → https://md.groupants.elamur.ai/free/en/mova/wasi-host/examples/mlab_gate.rs.groupant/