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breadth-05: Memory capability domains

Agent report: partial Review pending

Session: completed

docs/spec-fabric-mem.md, lines 1761–1767

The set notation above is the human rendering of canonical singleton/range domains. Alignment values are exponents: `[0, 63]` admits byte alignments `2^0` through `2^63`. Both classes remain inside one physical capability alternative, so endpoint bindings, actor-contract admission, and use-pattern references are not duplicated. Contiguous `vector<2xf64>` is rejected because element width 64 is absent even though its total payload also has 128 bits.

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.

No author explanation recorded.

Reported numeric verdicts

verdicts

64bitx2lane admissions

0

admitted shape counts

16x1

40

32x1

50

32x4

48

8x1

28

alignment probe per seed

exponent 64 65

CREATE_REJECT

exponents 0 1 32 62 63

CREATE_OK, containsBytes(2^k)=yes

range 0 63

CREATE_OK, containsBytes(2^0)=1, containsBytes(2^63)=1

range 0 64

CREATE_REJECT

driver return codes

0 on all 100 seeds

fail

0

invalid

0

pass

1200

rejected total

1034

seeds containing 64bitx2lane case

27

Tested obligations

• O1 alignment exponents: [0,63] canonical, 2^0..2^63 members, exponent 64/65 and [0,64] rejected
• O2 one alternative with two access classes: element {8,16,32}x1 and contiguous {32}x4 admitted
• O3 payload bits are not an admission criterion: contiguous 64-bit x 2 lanes (128-bit payload) rejected

Untested obligations

• non-duplication of endpoint bindings / actor-contract admission / use-pattern references inside the single alternative
• canonical byte-encoding round trip of the rendered set notation
• mask forms other than absent, stores, atomics, pointer-addressed views, read/write subword semantics

Format

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: {'property_checks': {'fail': 0, 'invalid': 0, 'pass': 1200}, 'seeds': 100, 'subject_exit_codes': {'0': 100}, 'subject_invocations': 100}
Baseline: No matching baseline measured
Minimized cases: not measured

Published evidence