core/generate/math_realizer.py
Shay 5a0423cb36
feat(derivation): Gate A2b case 0002 fractional rest composition (#810)
* 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
2026-06-17 19:08:24 -07:00

455 lines
18 KiB
Python

"""ADR-0118 — Stepped realizer: SolutionTrace → show-your-work prose.
Consumes a :class:`SolutionTrace` (ADR-0116) and emits a sequence of
one-sentence-per-step English explanations of the reasoning. The
realizer is **deterministic and pack-grounded**: every sentence
identifies the actor, the pack-resolved operation, and the operand,
ending with the answer sentence that names the resolved unknown.
Architectural commitments:
- **Deterministic.** Same trace → byte-identical prose.
- **Pack-grounded surface.** The verb in each step sentence is
drawn from a fixed table keyed to the operation kind; the kind
itself comes from the trace's ``pack_lemma_id``. Removing the
arithmetic pack breaks the trace upstream, which breaks the
realizer with a typed refusal.
- **Round-trippable** for add / subtract / transfer steps: the
rendered prose, when re-parsed by ``parse_problem``, yields a
graph whose solver-trace reproduces the same answer. ``multiply``
and ``divide`` step phrasings are deliberately one-way (the
parser's multiply pattern requires a possessed object phrase
that the realizer can simulate, but the divide phrasing requires
case-specific structure the parser does not yet recover). Round-
trippability is enforced on the operation kinds the parser fully
supports today; the divide / multiply cases produce inspectable
prose without the round-trip guarantee.
- **Typed refusal** on inconsistent traces (the realizer does not
re-validate the trace — :class:`ADR-0117 verifier`'s job — but
it does refuse unknown operation kinds).
The realizer is the ADR-0114a Obligation #5-compatible substrate
for ADR-0119's GSM8K eval lane: every "correct" answer in the lane
ships with a stepped explanation that traces to pack lemmas.
"""
from __future__ import annotations
import json
from dataclasses import dataclass
from typing import Any
from generate.math_problem_graph import Comparison, Rate
from generate.math_solver import SolutionStep, SolutionTrace
class RealizerError(ValueError):
"""Raised on unrecognized operation kind or empty trace."""
@dataclass(frozen=True, slots=True)
class RealizedTrace:
"""Stepped explanation surface for a :class:`SolutionTrace`.
``setup_sentences`` introduce the initial state (one sentence per
:class:`InitialPossession`). ``step_sentences`` walk the trace in
order. ``answer_sentence`` states the final resolved unknown.
``canonical_bytes()`` is byte-deterministic so two realizations of
the same trace produce the same SHA-256.
"""
setup_sentences: tuple[str, ...]
step_sentences: tuple[str, ...]
answer_sentence: str
pack_id: str
def as_json(self) -> dict[str, Any]:
return {
"setup_sentences": list(self.setup_sentences),
"step_sentences": list(self.step_sentences),
"answer_sentence": self.answer_sentence,
"pack_id": self.pack_id,
}
def canonical_bytes(self) -> bytes:
return json.dumps(
self.as_json(), sort_keys=True, separators=(",", ":")
).encode("utf-8")
def as_prose(self) -> str:
"""Join setup + step + answer sentences into one paragraph."""
sentences = list(self.setup_sentences) + list(self.step_sentences)
sentences.append(self.answer_sentence)
return " ".join(sentences)
def realize(graph_initial_state: tuple, trace: SolutionTrace) -> RealizedTrace:
"""Render a :class:`SolutionTrace` as show-your-work prose.
``graph_initial_state`` is the input graph's ``initial_state`` tuple
(used to introduce the entities and their starting quantities).
``trace`` provides the per-step records and the resolved answer.
Pure function; same inputs → byte-identical output. Raises
:class:`RealizerError` on empty traces or unrecognized step kinds.
"""
if not isinstance(trace, SolutionTrace):
raise RealizerError(
f"trace must be a SolutionTrace, got {type(trace).__name__}"
)
setup_sentences = tuple(
_setup_sentence(p.entity, p.quantity.value, p.quantity.unit)
for p in graph_initial_state
)
# ADR-0123: the multiplicative comparison helper needs the
# reference actor's unit, which is not stored on Comparison when
# factor is set. We derive it deterministically from initial
# state — the only entity-unit binding the realizer can reach
# without re-running the solver. This is sufficient because the
# substrate refuses multi-unit reference actors at solve time.
entity_units: dict[str, str] = {
p.entity: p.quantity.unit for p in graph_initial_state
}
step_sentences: list[str] = []
for step in trace.steps:
step_sentences.append(_step_sentence(step, entity_units))
answer_sentence = _answer_sentence(
trace.answer_entity, trace.answer_value, trace.answer_unit
)
return RealizedTrace(
setup_sentences=setup_sentences,
step_sentences=tuple(step_sentences),
answer_sentence=answer_sentence,
pack_id=trace.pack_id,
)
def _setup_sentence(entity: str, value: int | float, unit: str) -> str:
return f"{entity} has {_render_number(value)} {_unit_surface(unit, value)}."
def _step_sentence(
step: SolutionStep, entity_units: dict[str, str] | None = None
) -> str:
if step.operation_kind == "apply_rate":
return _apply_rate_sentence(step)
if step.operation_kind == "compare_additive":
return _compare_additive_sentence(step)
if step.operation_kind == "compare_multiplicative":
if entity_units is None:
raise RealizerError(
f"compare_multiplicative step {step.step_index} requires "
f"entity_units to resolve reference actor unit; got None"
)
return _compare_multiplicative_sentence(step, entity_units)
if step.operation_kind == "add":
return (
f"{step.actor} buys {_render_number(step.operand.value)} more "
f"{_unit_surface(step.operand.unit, step.operand.value)}, "
f"raising the total to {_render_number(step.after_value)}."
)
if step.operation_kind == "subtract":
return (
f"{step.actor} loses {_render_number(step.operand.value)} "
f"{_unit_surface(step.operand.unit, step.operand.value)}, "
f"leaving {_render_number(step.after_value)}."
)
if step.operation_kind == "transfer":
if step.target is None:
raise RealizerError(
f"transfer step {step.step_index} missing target"
)
return (
f"{step.actor} gives {_render_number(step.operand.value)} "
f"{_unit_surface(step.operand.unit, step.operand.value)} to "
f"{step.target}, leaving {step.actor} with "
f"{_render_number(step.after_value)}."
)
if step.operation_kind == "multiply":
verb = "doubles" if step.operand.value == 2 else (
"triples" if step.operand.value == 3 else "multiplies"
)
if verb == "multiplies":
return (
f"{step.actor} multiplies their "
f"{_unit_surface(step.operand.unit, 2)} by "
f"{_render_number(step.operand.value)}, "
f"reaching {_render_number(step.after_value)}."
)
return (
f"{step.actor} {verb} their "
f"{_unit_surface(step.operand.unit, 2)}, "
f"reaching {_render_number(step.after_value)}."
)
if step.operation_kind == "divide":
return (
f"{step.actor} splits their "
f"{_unit_surface(step.operand.unit, 2)} evenly into "
f"{_render_number(step.operand.value)} groups and keeps one "
f"group, leaving {_render_number(step.after_value)}."
)
if step.operation_kind == "unit_partition":
from generate.math_problem_graph import PartitionChunk
if not isinstance(step.operand, PartitionChunk):
raise RealizerError(
f"unit_partition step {step.step_index} requires "
f"PartitionChunk operand"
)
chunk = step.operand
return (
f"{step.actor} splits {_render_number(step.before_value)} "
f"{_unit_surface(chunk.unit, step.before_value)} into "
f"{_render_number(chunk.value)}-{_singular(chunk.unit)} "
f"{_unit_surface(chunk.result_unit, step.after_value)}, "
f"yielding {_render_number(step.after_value)} "
f"{_unit_surface(chunk.result_unit, step.after_value)}."
)
if step.operation_kind == "fraction_portion":
from generate.math_problem_graph import FractionPortion
if not isinstance(step.operand, FractionPortion):
raise RealizerError(
f"fraction_portion step {step.step_index} requires "
f"FractionPortion operand"
)
portion = step.operand
removed = step.before_value - step.after_value
return (
f"{step.actor} gives away {_render_number(removed)} "
f"({_render_number(portion.numerator)}/"
f"{_render_number(portion.denominator)} of the prior total), "
f"leaving {_render_number(step.after_value)}."
)
raise RealizerError(
f"step {step.step_index} has unknown operation_kind "
f"{step.operation_kind!r}"
)
def _apply_rate_sentence(step: SolutionStep) -> str:
"""Render an apply_rate step as show-your-work prose (ADR-0122).
The template intentionally contains both ``"<value> <numer> per
<denom-singular>"`` (the rate clause) and ``"<after> <numer>"``
(the computed total), which the test suite pins as a structural
invariant. The denominator phrase uses singular form (``per
apple``) regardless of count, matching natural English.
"""
if not isinstance(step.operand, Rate):
raise RealizerError(
f"apply_rate step {step.step_index} requires a Rate "
f"operand; got {type(step.operand).__name__}"
)
rate = step.operand
rate_n = _render_number(rate.value)
before_n = _render_number(step.before_value)
after_n = _render_number(step.after_value)
denom_singular = _singular(rate.denominator_unit)
denom_surface = _unit_surface(rate.denominator_unit, step.before_value)
return (
f"At {rate_n} {rate.numerator_unit} per {denom_singular}, "
f"{step.actor} spends {after_n} {rate.numerator_unit} on "
f"{before_n} {denom_surface}."
)
def _compare_additive_sentence(step: SolutionStep) -> str:
"""Render an additive comparison step as show-your-work prose (ADR-0123).
Reads ``step.operand`` (must be a :class:`Comparison` with
``delta`` set) and emits a one-sentence rendering of the form:
- direction='more': "<actor> has <delta> more <unit> than <ref>,
giving <actor> a total of <after> <unit>."
- direction='fewer': "<actor> has <delta> fewer <unit> than <ref>,
leaving <actor> with a total of <after> <unit>."
The two-clause shape — *comparison clause* + *resolved state* —
is pinned as a structural invariant by the ADR-0123 test suite.
``delta.value`` and ``after_value`` pluralize independently via
:func:`_unit_surface` (so "1 more apple" vs "3 more apples"
behave correctly without the resolved state being forced into
the same plurality).
Raises :class:`RealizerError` on:
- operand not a :class:`Comparison` (substrate solver bug)
- missing ``delta`` (multiplicative shape leaked into this branch)
- direction not in ``{"more", "fewer"}``
- self-reference (actor == reference_actor)
"""
if not isinstance(step.operand, Comparison):
raise RealizerError(
f"compare_additive step {step.step_index} requires a "
f"Comparison operand; got {type(step.operand).__name__}"
)
cmp = step.operand
if cmp.delta is None:
raise RealizerError(
f"compare_additive step {step.step_index} requires "
f"Comparison.delta; got None (multiplicative shape leaked)"
)
if cmp.direction not in ("more", "fewer"):
raise RealizerError(
f"compare_additive step {step.step_index} requires "
f"direction in {{'more','fewer'}}; got {cmp.direction!r}"
)
if step.actor == cmp.reference_actor:
raise RealizerError(
f"compare_additive step {step.step_index} refuses "
f"self-comparison: actor=={cmp.reference_actor!r}"
)
delta_n = _render_number(cmp.delta.value)
after_n = _render_number(step.after_value)
delta_surface = _unit_surface(cmp.delta.unit, cmp.delta.value)
after_surface = _unit_surface(cmp.delta.unit, step.after_value)
if cmp.direction == "more":
return (
f"{step.actor} has {delta_n} more {delta_surface} than "
f"{cmp.reference_actor}, giving {step.actor} a total of "
f"{after_n} {after_surface}."
)
# direction == "fewer"
return (
f"{step.actor} has {delta_n} fewer {delta_surface} than "
f"{cmp.reference_actor}, leaving {step.actor} with a total of "
f"{after_n} {after_surface}."
)
def _compare_multiplicative_sentence(
step: SolutionStep, entity_units: dict[str, str]
) -> str:
"""Render a multiplicative comparison step as show-your-work prose.
Reads ``step.operand`` (must be a :class:`Comparison` with
``factor`` set) and emits:
- direction='times': "<actor> has <factor> times as many <unit>
as <ref>, giving <actor> a total of <after>
<unit>."
- direction='fraction', factor==0.5:
"<actor> has half as many <unit> as <ref>,
giving <actor> a total of <after> <unit>."
- direction='fraction', other factor:
"<actor> has <factor> as many <unit> as
<ref>, giving <actor> a total of <after>
<unit>."
``unit`` is resolved from ``entity_units[reference_actor]`` — the
substrate's solver derives it from the reference actor's
in-flight state, but the realizer only sees ``SolutionStep``
instances. Initial-state lookup is sufficient because the
substrate refuses multi-unit reference actors and refuses to
overwrite a comparison actor's existing state.
Raises :class:`RealizerError` on:
- operand not a :class:`Comparison`
- missing ``factor``
- direction not in ``{"times", "fraction"}``
- reference actor missing from ``entity_units``
- self-reference
"""
if not isinstance(step.operand, Comparison):
raise RealizerError(
f"compare_multiplicative step {step.step_index} requires "
f"a Comparison operand; got {type(step.operand).__name__}"
)
cmp = step.operand
if cmp.factor is None:
raise RealizerError(
f"compare_multiplicative step {step.step_index} requires "
f"Comparison.factor; got None (additive shape leaked)"
)
if cmp.direction not in ("times", "fraction"):
raise RealizerError(
f"compare_multiplicative step {step.step_index} requires "
f"direction in {{'times','fraction'}}; got {cmp.direction!r}"
)
if step.actor == cmp.reference_actor:
raise RealizerError(
f"compare_multiplicative step {step.step_index} refuses "
f"self-comparison: actor=={cmp.reference_actor!r}"
)
if cmp.reference_actor not in entity_units:
raise RealizerError(
f"compare_multiplicative step {step.step_index} requires "
f"reference actor {cmp.reference_actor!r} to appear in "
f"initial state; available entities: "
f"{sorted(entity_units)!r}"
)
unit = entity_units[cmp.reference_actor]
after_n = _render_number(step.after_value)
after_surface = _unit_surface(unit, step.after_value)
if cmp.direction == "fraction" and cmp.factor == 0.5:
return (
f"{step.actor} has half as many {unit} as "
f"{cmp.reference_actor}, giving {step.actor} a total of "
f"{after_n} {after_surface}."
)
factor_n = _render_number(cmp.factor)
if cmp.direction == "fraction":
return (
f"{step.actor} has {factor_n} as many {unit} as "
f"{cmp.reference_actor}, giving {step.actor} a total of "
f"{after_n} {after_surface}."
)
# direction == "times"
return (
f"{step.actor} has {factor_n} times as many {unit} as "
f"{cmp.reference_actor}, giving {step.actor} a total of "
f"{after_n} {after_surface}."
)
def _answer_sentence(
entity: str | None, value: int | float, unit: str
) -> str:
if entity is None:
return (
f"In total, they have {_render_number(value)} "
f"{_unit_surface(unit, value)}."
)
return (
f"{entity} has {_render_number(value)} "
f"{_unit_surface(unit, value)}."
)
def _render_number(value: int | float) -> str:
"""Render numeric value preferring integer form when exact."""
if isinstance(value, bool):
# bool is a subclass of int — refuse explicitly
raise RealizerError(f"cannot render boolean as number: {value!r}")
if isinstance(value, float) and value.is_integer():
return str(int(value))
return str(value)
def _unit_surface(unit: str, value: int | float) -> str:
"""Render a unit string in surface form.
Quantities of exactly 1 take the singular; all others keep the
canonical plural. This matches the parser's
``_canonical_unit`` round-trip — the parser maps singular surfaces
back to plural at graph time.
"""
if value == 1:
return _singular(unit)
return unit
def _singular(unit: str) -> str:
if unit.endswith("ies") and len(unit) > 3:
return unit[:-3] + "y"
if unit.endswith("es") and len(unit) > 2 and unit[-3:-2] in {"s", "x", "z"}:
return unit[:-2]
if unit.endswith("s") and not unit.endswith("ss"):
return unit[:-1]
return unit