* feat(derivation): Gate A2b case 0002 fractional rest composition
Add fraction_portion operation for "gives N/M of that" and "half of the
rest" subtract semantics chained after unit_partition, plus keep-on-hand
question binding with partition-noun unit inference. Live train_sample
moves 6/44/0 to 7/43/0 with wrong=0 preserved; confuser-v1-0007 still
refuses without "of that".
* test(derivation): add A2b sibling and confuser anti-overfit cases
Cover Bob/Alice partition+fraction chains, slash-without-referent refusal,
partition-less "of that", and multi-actor pronoun ambiguity.
* chore(derivation): normalize A2b fraction test EOF
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>
Phase 2 of the ADR-0114 expert-capability roadmap. Consumes the
MathProblemGraph from Phase 1 and emits a SolutionTrace — ordered
operation applications ending at a numeric answer, byte-deterministic
across runs, with each step's operation bound to a pack-resolved
lemma identifier.
What landed
generate/math_solver.py
- solve(graph) -> SolutionTrace; pure function, no I/O, no globals
- SolutionStep dataclass with before/after values per step (for
verifier replay; ADR-0117 hardens)
- SolutionTrace with canonical_bytes() byte-deterministic JSON
- SolveError typed refusal: missing pack, division by zero,
unknown-references-nothing
language_packs/data/en_arithmetic_v1/
- 5 operator lemmas: add / subtract / multiply / divide / transfer
- role=operational_base (vocabulary-only; no domain claim)
- SHA-256-anchored lexicon + glosses; manifest carries
provenance=adr-0116:operator_seed:2026-05-22
tests/test_math_solver.py — 109 cases pinning five invariants:
1. Phase 2 exit criterion: ≥ 0.80 on parser-correct dev set
(current: 50/50 = 1.00)
2. Determinism: two solves produce byte-equal trace
3. Trace replay reproduces answer_value (verifier rehearsal)
4. Typed refusal on under-determined inputs
5. Every step.pack_lemma_id resolves to a real lexicon entry
in en_arithmetic_v1
ADR-0114a obligation discharge
Four of ten anti-overfitting obligations now have load-bearing
implementations in code:
#3 replay-equal trace — discharged (solver-layer)
#4 typed refusal — discharged (solver-layer)
#9 determinism — discharged (solver-layer)
#10 operation provenance via pack — DISCHARGED IN FULL
Removing the en_arithmetic_v1 pack now breaks every solve loudly.
The "operations bind to concepts, not hardcoded strings" claim is
architecturally true, not rhetorical.
Tests: 109/109 green on solver suite; 67/67 smoke suite green;
parser + schema suites still green from prior phases.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
