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breadth-10: Boundary directions

Agent report: complete Review pending

Session: completed

docs/spec-fabric-boundary.md, lines 14–27

## Direction predicate Every `fabric.boundary` op carries a mandatory `direction` attribute printed/parsed as a bracketed predicate, mirroring `fabric.pe`'s `[spatial|temporal]` style: ```mlir fabric.boundary [s2t] ... fabric.boundary [t2t] ... fabric.boundary [t2s] ... ``` The keyword between `[` and `]` is one of `s2t`, `t2t`, `t2s`. The parser rejects any other keyword.

Execution provenance

The original pilot recorded the compiler hash and checkout revision separately; its binary build revision was not verified. Coverage follow-ups use separately identified rebuilt binaries. Original simulator binary hashes were not retained.

Original standalone-test agent report

This is exploratory evidence, not an accepted production-format PBT.

All obligations of the selected passage (docs/spec-fabric-boundary.md:14-27) are exercised against the real pinned subject. Obligations outside the passage are out of scope and listed under untested_obligations.

Reported numeric verdicts

not measured

Tested obligations

• id

  P1

  result

  held on 46 cases

  text

  keyword one of s2t/t2t/t2s is accepted by the parser

• id

  P2

  result

  held on 54 cases

  text

  the parser rejects any other keyword (rejection attributable to the bracketed predicate: non-zero exit and diagnostic located inside [...])

• id

  P3

  result

  held on 46 cases

  text

  direction is printed as a bracketed predicate; accepted op prints back exactly one 'fabric.boundary [kw]' with the same keyword

• id

  P4

  result

  held on 46 cases

  text

  printed/parsed round-trip is stable (reparse of printed form succeeds and reprints identically)

• id

  P5

  result

  held; observed s2t=0, t2t=1, t2s=2 (integer encoding treated as observation, not as a documented obligation)

  text

  mandatory direction attribute present in the IR (generic form shows exactly one direction = N : i32) and keyword<->N is a consistent bijection

Untested obligations

• Diagnostic wording (deliberately not frozen: the same document's Validation Anchors say tests do not freeze diagnostic wording).
• All clauses of spec-fabric-boundary.md outside lines 14-27: handshake/atomic-transfer equations, Configured Projection / sw_configs / hw_params rules, per-direction verifier width rules, placement inside fabric.module, inner_input_types, ConfigurationABI ownership, canonicalization of empty t2t LUT.
• Direction predicate appearing in contexts other than a fabric.module body (placement is a separate section).

Format

chosen

standalone Python generator + Python output/diagnostic assertions

reason

The passage's central clause is parser rejection; rejected inputs produce no output generic MLIR, so the spectriad-check PROPERTY INPUT.generic.mlir OUTPUT.generic.mlir contract cannot express the negative half. Exit codes and diagnostic source locations are also outside that checker's input model. ProGRMR/.spct not used.

Reproduction

Measured subject code coverage

measured · Measured handwritten Loom subject code only; external LLVM/MLIR and generated code excluded. Includes main executions, including rejected inputs; deliberate controls excluded. No matching native-suite baseline for this executable has been imported, so no coverage gain is claimed. Semantic fidelity remains a separate audit.

Execution: {'subject_exit_codes': {'0': 138, '1': 108}, 'subject_invocations': 246}
Baseline: No matching baseline measured
Minimized cases: not measured

Published evidence