Second parser-expansion ADR after ADR-0122 rate/per-unit. Adds the
comparison algebra substrate (Comparison dataclass + compare_additive /
compare_multiplicative operation kinds + parser patterns + solver /
verifier / pack lemmas) mirroring the substrate-only / lift-deferred
pattern ADR-0122 established.
Substrate
- Comparison(reference_actor, delta: Quantity|None, factor: float|None,
direction: Literal[more,fewer,times,fraction]) frozen dataclass with
direction-discriminated delta/factor enforcement and self-reference
refusal at the Operation boundary
- compare_additive + compare_multiplicative operation kinds admitted in
VALID_OPERATION_KINDS; Operation.operand widened to Quantity|Comparison
with kind-discriminated type enforcement; entity-set validation extended
to cover Comparison.reference_actor
- Parser: _COMPARE_ADDITIVE_RE (more/fewer/less), _COMPARE_TWICE_RE,
_COMPARE_N_TIMES_RE, _COMPARE_HALF_RE happy-path patterns + 5
refusal patterns (ambiguous 'N times more', age comparisons,
combined-with-aggregation, nested additive+multiplicative); inserted
before _try_initial so leading 'has <N>' shape is not greedily
consumed as initial possession with unit='more'/'fewer'
- Solver: _apply_compare_additive (refuses on missing reference state,
overwrite, negative result); _apply_compare_multiplicative (refuses
on missing reference, ambiguous multi-unit reference, overwrite);
unit comes from delta.unit (additive) or reference's unique unit
(multiplicative)
- Verifier: _verify_compare_additive_step + _verify_compare_multiplicative_step
byte-equal replay; tamper-detects after_value, direction, factor
- Pack: en-arith-006 compare_additive + en-arith-007 compare_multiplicative
lemmas + glosses; SHA-256 checksums refreshed; manifest 1.0.0 -> 1.1.0;
provenance tagged adr-0123:comparison_extension:2026-05-23
Measurement (honest; from Gemini empirical sealed run on parallel surface
branch with this substrate)
- Sealed GSM8K correct_rate: 0/1319 (substrate matches zero real cases
alone). Validates the ADR-0122 multi-construction barrier prediction:
comparison constructions in GSM8K rarely appear alone — they bind with
rate (ADR-0124), percentage (ADR-0125), aggregation (ADR-0126), or
conditional ('if') clauses. First lift signal requires composition.
- Sealed GSM8K wrong: 0 (load-bearing positive claim; ADR-0114a
Obligation #4 preserved across all 1,319 sealed problems)
- Regression safety: 0 — all 913 non-comparison cases continue to
refuse exactly as before (refused_parser), no greedy consumption by
the new comparison patterns
Surface-form catalog (from Gemini Task 2 survey, see ADR doc) covers
6 primary forms across Groups A/B/C; Groups D (age), E (combined with
aggregation), F (nested additive+multiplicative) refused as out-of-scope
with typed ParseError naming the missing companion ADR.
Branch isolation
- Landed via dedicated worktree (feat/adr-0123-substrate from origin/main)
after a file-race on the shared umbrella branch. Companion surface +
scaffolding (realizer, ADR doc, tests, README) lands separately as
feat/adr-0123-surface; orchestrator merges both into the umbrella
feat/adr-0123-comparison-phrasing.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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