Canonical bytes need a declared value language¶
GA-SYN-005 · Edition 2026.10.8 · Synthetic technical investigation
Proposition and operational question¶
Length-framed pairs round-trip without collisions over 25 pairs of five lowercase strings; dropping the framing makes distinct pairs collide.
This matters when a continuing task reuses an earlier decision or representation. A final success label can conceal a different failure earlier in the trace. The proposition therefore identifies the exact observation that would refute it.
Definitions, trust and failure model¶
The values are exactly two lowercase ASCII strings. The teaching format writes each string length as a minimal decimal integer, a colon and the string. The parser consumes exactly two fields and rejects trailing material. This independently designed text exercise is not a native wire representation, and supplies no signatures, semantic objects or authorization.
Worked synthetic trace¶
The pair (a,bc) becomes 1:a2:bc; (ab,c) becomes 2:ab1:c. Reading the first length consumes exactly a, then the second consumes bc. A leading-zero length such as 01:a1:b is rejected rather than silently normalized. So are trailing material, a truncated value and an uppercase field. The checker enumerates the declared 25 pairs and verifies exact round trips and unique byte strings.
Negative control¶
Concatenation without lengths maps both (a,bc) and (ab,c) to abc. Decoding cannot recover which value was intended. A separate numeric counterexample is 256: it fits an unsigned sixteen-bit carrier and fails an unsigned eight-bit carrier. Deterministic encoders can therefore agree on every small vector while accepting different value sets. Compilation does not repair the disagreement.
Three evidence records and separate axes¶
| Record | Method and evidence | Scope and status |
|---|---|---|
| Research | Authored finite argument and explicit counterexample, 12 October 2026 | Analytical; limited to the definitions above |
| Reference | My execution, with AI assistance, of the independently designed public teaching case encoding, 12 October 2026 |
Fault-tested; externally reproducible with the commands below; no independent reproduction claimed |
| Production | None for this proposition | No product conformance inferred |
Engineering maturity: reference_implemented, referring only to the disclosed teaching case. Assurance: analytical, fault_tested, externally_reproducible, each restricted to its evidence record. These labels are independent dimensions, not a score or a global verification flag. The exact machine-readable record is in the public evidence catalog. My own runs do not count as independent review.
Limitations and open obligations¶
The checked alphabet and pair population are finite. General injectivity requires an argument about minimal lengths and exact consumption beyond these tests. Unicode, numeric normalization, recursion, transport defaults and duplicate names are outside this model. The native AD8 reference and generated carriers have separately unresolved compatibility obligations; this example neither exports them nor proves their equivalence. Hashing canonical bytes establishes an identity only after the semantic value domain is fixed.
Prior art and contribution limit¶
Build provenance identifies artifacts and inputs; it does not establish semantic equivalence. Length framing and canonical representations are standard techniques. The contribution here is the explicit test boundary and a counterexample to inferring a shared value language from matching outputs on a subset. Compare the established JCS and CBOR specifications. See also the primary reference and the comparison guide. No priority or superiority claim follows from this example.
Reproduction and falsification¶
From the successor public source package, use CPython 3.12.14 and no external packages:
python examples/investigations/check.py --case encoding
python examples/investigations/check.py --case encoding --mutant
The first command must exit zero, with no positive violations and at least one negative violation. The second intentionally exits one and prints an actual violated case. It is a deliberate fault result, not an installation failure. Source and reproduction contract identify the exact population and scope.
Submit a counterexample, a missing assumption or a prior-art correction through the review guide. Include GA-SYN-005, edition 2026.10.8, the command, input and output, and whether the objection concerns the model, implementation or proposed product relationship. Do not send credentials or confidential customer material.
For the wider architecture, see the AD8 paper, architecture synthesis, claim register, and AD8 investigation overview. Native reference results and open constructions have separate scope; these examples do not implement them.