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FA-96881 / Recipe scaling and nutrition / Open access

Nutrition label rounding: fat half-gram band · case 01

2.25 g of fat prints as 2 g instead of 2.5 g.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Fat between 0.5 and 5 g is rounded to whole grams instead of half grams.

VERIFIED REPAIR

Use the 0.5 g step for fat below 5 g.

Unsuccessful approach: Limiting the half-gram step to fat below 1 g rounds 1.25-4.9 g to whole grams.

Case contract

Round a panel dict to displayed strings (toy label rules, half-up): calories <5 -> 0, <=50 -> nearest 5, else nearest 10; fat g <0.5 -> 0, <5 -> nearest 0.5, else nearest 1; sodium mg <5 -> 0, <=140 -> nearest 5, else nearest 10; cholesterol mg <2 -> "0 mg", <5 -> "less than 5 mg", else nearest 5; carbs g <0.5 -> "0 g", <1 -> "less than 1 g", else nearest 1. Absent keys are omitted. Values print with %g formatting.

Why this case matters

Packaged food and meal-kit labels are generated from recipe nutrition totals with banded rounding rules that differ per nutrient.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
import math
from fractions import Fraction
N = 1
observations = []
def solve(panel):
    def near(x, step):
        return math.floor(x / step + Fraction(1, 2)) * step
    def show(v, unit):
        t = format(float(v), 'g')
        return t + ' ' + unit if unit else t
    out = {}
    if 'calories' in panel:
        c = Fraction(str(panel['calories']))
        out['calories'] = show(0 if c < 5 else near(c, 5) if c <= 50 else near(c, 10), '')
    if 'fat' in panel:
        x = Fraction(str(panel['fat']))
        out['fat'] = show(0 if x < Fraction(1, 2) else near(x, 1) if x < 5 else near(x, 1), 'g')
    if 'sodium' in panel:
        x = Fraction(str(panel['sodium']))
        out['sodium'] = show(0 if x < 5 else near(x, 5) if x <= 140 else near(x, 10), 'mg')
    if 'cholesterol' in panel:
        x = Fraction(str(panel['cholesterol']))
        out['cholesterol'] = '0 mg' if x < 2 else 'less than 5 mg' if x < 5 else show(near(x, 5), 'mg')
    if 'carbs' in panel:
        x = Fraction(str(panel['carbs']))
        out['carbs'] = '0 g' if x < Fraction(1, 2) else 'less than 1 g' if x < 1 else show(near(x, 1), 'g')
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['empty panel', [{}], {}],
  ['insignificant calories', [{'calories': 4.9, 'fat': 0.4}], {'calories': '0', 'fat': '0 g'}],
  ['mid-band sodium', [{'carbs': 0.9, 'sodium': 137.5}], {'carbs': 'less than 1 g', 'sodium': '140 mg'}],
  ['regression: fat half-gram band', [{'calories': 10.75, 'carbs': 0.9, 'fat': 0.5}],
   {'calories': '10', 'carbs': 'less than 1 g', 'fat': '0.5 g'}],
  ['repair check: fat half-gram band', [{'calories': 56, 'carbs': 0.2, 'fat': 1.25, 'sodium': 198}],
   {'calories': '60', 'carbs': '0 g', 'fat': '1.5 g', 'sodium': '200 mg'}],
  ['generated control 1', [{'calories': 43.25, 'carbs': 1.5, 'sodium': 145}],
   {'calories': '45', 'carbs': '2 g', 'sodium': '150 mg'}],
  ['generated control 2', [{'calories': 65.5, 'fat': 2.75, 'sodium': 131.5}],
   {'calories': '70', 'fat': '3 g', 'sodium': '130 mg'}],
  ['generated control 3', [{'calories': 44.25, 'carbs': 30.4, 'fat': 13}],
   {'calories': '45', 'carbs': '30 g', 'fat': '13 g'}]],
 [['insignificant calories', [{'calories': 4.9, 'fat': 0.4}], {'calories': '0', 'fat': '0 g'}],
  ['mid-band sodium', [{'carbs': 0.9, 'sodium': 137.5}], {'carbs': 'less than 1 g', 'sodium': '140 mg'}],
  ['large values', [{'calories': 245, 'cholesterol': 22.5, 'fat': 12.5, 'sodium': 455}],
   {'calories': '250', 'cholesterol': '25 mg', 'fat': '13 g', 'sodium': '460 mg'}],
  ['regression: fat half-gram band', [{'calories': 49.25, 'fat': 3.5, 'sodium': 143.5}],
   {'calories': '50', 'fat': '3.5 g', 'sodium': '140 mg'}],
  ['repair check: fat half-gram band', [{'calories': 3, 'cholesterol': 5, 'fat': 1.25, 'sodium': 189.5}],
   {'calories': '0', 'cholesterol': '5 mg', 'fat': '1.5 g', 'sodium': '190 mg'}],
  ['generated control 1', [{'calories': 5.25, 'fat': 2, 'sodium': 143}],
   {'calories': '5', 'fat': '2 g', 'sodium': '140 mg'}],
  ['generated control 2', [{'calories': 0.25, 'carbs': 1, 'cholesterol': 3, 'fat': 17.75, 'sodium': 3}],
   {'calories': '0', 'carbs': '1 g', 'cholesterol': 'less than 5 mg', 'fat': '18 g', 'sodium': '0 mg'}],
  ['generated control 3', [{'calories': 45.5, 'cholesterol': 3, 'fat': 4.75, 'sodium': 7.5}],
   {'calories': '45', 'cholesterol': 'less than 5 mg', 'fat': '5 g', 'sodium': '10 mg'}]],
 [['mid-band sodium', [{'carbs': 0.9, 'sodium': 137.5}], {'carbs': 'less than 1 g', 'sodium': '140 mg'}],
  ['large values', [{'calories': 245, 'cholesterol': 22.5, 'fat': 12.5, 'sodium': 455}],
   {'calories': '250', 'cholesterol': '25 mg', 'fat': '13 g', 'sodium': '460 mg'}],
  ['small cholesterol', [{'carbs': 12.5, 'cholesterol': 3}],
   {'carbs': '13 g', 'cholesterol': 'less than 5 mg'}],
  ['regression: fat half-gram band', [{'calories': 12.5, 'cholesterol': 22.5, 'fat': 0.5, 'sodium': 120.5}],
   {'calories': '15', 'cholesterol': '25 mg', 'fat': '0.5 g', 'sodium': '120 mg'}],
  ['repair check: fat half-gram band', [{'calories': 2.5, 'fat': 2.5, 'sodium': 197.5}],
   {'calories': '0', 'fat': '2.5 g', 'sodium': '200 mg'}],
  ['generated control 1', [{'calories': 2.25, 'fat': 4, 'sodium': 7.5}],
   {'calories': '0', 'fat': '4 g', 'sodium': '10 mg'}],
  ['generated control 2', [{'calories': 270, 'carbs': 1.5, 'fat': 6, 'sodium': 3.25}],
   {'calories': '270', 'carbs': '2 g', 'fat': '6 g', 'sodium': '0 mg'}],
  ['generated control 3', [{'calories': 0, 'cholesterol': 2, 'fat': 0.4, 'sodium': 0.25}],
   {'calories': '0', 'cholesterol': 'less than 5 mg', 'fat': '0 g', 'sodium': '0 mg'}]],
 [['large values', [{'calories': 245, 'cholesterol': 22.5, 'fat': 12.5, 'sodium': 455}],
   {'calories': '250', 'cholesterol': '25 mg', 'fat': '13 g', 'sodium': '460 mg'}],
  ['small cholesterol', [{'carbs': 12.5, 'cholesterol': 3}],
   {'carbs': '13 g', 'cholesterol': 'less than 5 mg'}],
  ['empty panel', [{}], {}],
  ['regression: fat half-gram band', [{'calories': 241, 'cholesterol': 2, 'fat': 0.5, 'sodium': 142.5}],
   {'calories': '240', 'cholesterol': 'less than 5 mg', 'fat': '0.5 g', 'sodium': '140 mg'}],
  ['repair check: fat half-gram band', [{'calories': 185.5, 'cholesterol': 7.5, 'fat': 3.5, 'sodium': 122}],
   {'calories': '190', 'cholesterol': '10 mg', 'fat': '3.5 g', 'sodium': '120 mg'}],
  ['generated control 1', [{'calories': 4.6, 'fat': 10.5, 'sodium': 12.5}],
   {'calories': '0', 'fat': '11 g', 'sodium': '15 mg'}],
  ['generated control 2', [{'calories': 365.5, 'carbs': 12.5, 'cholesterol': 2, 'sodium': 3.5}],
   {'calories': '370', 'carbs': '13 g', 'cholesterol': 'less than 5 mg', 'sodium': '0 mg'}],
  ['generated control 3', [{'calories': 2.5, 'carbs': 0.9, 'fat': 18}],
   {'calories': '0', 'carbs': 'less than 1 g', 'fat': '18 g'}]],
 [['small cholesterol', [{'carbs': 12.5, 'cholesterol': 3}],
   {'carbs': '13 g', 'cholesterol': 'less than 5 mg'}],
  ['empty panel', [{}], {}],
  ['insignificant calories', [{'calories': 4.9, 'fat': 0.4}], {'calories': '0', 'fat': '0 g'}],
  ['regression: fat half-gram band', [{'calories': 56.25, 'carbs': 1.5, 'fat': 1.25}],
   {'calories': '60', 'carbs': '2 g', 'fat': '1.5 g'}],
  ['repair check: fat half-gram band', [{'calories': 156.5, 'carbs': 0.2, 'fat': 4.5, 'sodium': 132}],
   {'calories': '160', 'carbs': '0 g', 'fat': '4.5 g', 'sodium': '130 mg'}],
  ['generated control 1', [{'carbs': 1, 'fat': 5.5}], {'carbs': '1 g', 'fat': '6 g'}],
  ['generated control 2', [{'calories': 9, 'sodium': 12.5}], {'calories': '10', 'sodium': '15 mg'}],
  ['generated control 3', [{'calories': 85.5, 'carbs': 1.5, 'cholesterol': 3, 'fat': 1, 'sodium': 7}],
   {'calories': '90', 'carbs': '2 g', 'cholesterol': 'less than 5 mg', 'fat': '1 g', 'sodium': '5 mg'}]]]
for label, args, expected in fixtures[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
empty panel{}{}Passed
insignificant calories{'calories': '0', 'fat': '0 g'}{'calories': '0', 'fat': '0 g'}Passed
mid-band sodium{'carbs': 'less than 1 g', 'sodium': '140 mg'}{'carbs': 'less than 1 g', 'sodium': '140 mg'}Passed
regression: fat half-gram band{'calories': '10', 'carbs': 'less than 1 g', 'fat': '1 g'}{'calories': '10', 'carbs': 'less than 1 g', 'fat': '0.5 g'}Failed
repair check: fat half-gram band{'calories': '60', 'carbs': '0 g', 'fat': '1 g', 'sodium': '200 mg'}{'calories': '60', 'carbs': '0 g', 'fat': '1.5 g', 'sodium': '200 mg'}Failed
generated control 1{'calories': '45', 'carbs': '2 g', 'sodium': '150 mg'}{'calories': '45', 'carbs': '2 g', 'sodium': '150 mg'}Passed
generated control 2{'calories': '70', 'fat': '3 g', 'sodium': '130 mg'}{'calories': '70', 'fat': '3 g', 'sodium': '130 mg'}Passed
generated control 3{'calories': '45', 'carbs': '30 g', 'fat': '13 g'}{'calories': '45', 'carbs': '30 g', 'fat': '13 g'}Passed

SHA-256 / ca919c7feb1c1d28890e930be4ef46a365e3418c243b1035db2bcc43a4261c74

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
import math
from fractions import Fraction
N = 1
observations = []
def solve(panel):
    def near(x, step):
        return math.floor(x / step + Fraction(1, 2)) * step
    def show(v, unit):
        t = format(float(v), 'g')
        return t + ' ' + unit if unit else t
    out = {}
    if 'calories' in panel:
        c = Fraction(str(panel['calories']))
        out['calories'] = show(0 if c < 5 else near(c, 5) if c <= 50 else near(c, 10), '')
    if 'fat' in panel:
        x = Fraction(str(panel['fat']))
        out['fat'] = show(0 if x < Fraction(1, 2) else near(x, Fraction(1, 2)) if x < 1 else near(x, 1), 'g')
    if 'sodium' in panel:
        x = Fraction(str(panel['sodium']))
        out['sodium'] = show(0 if x < 5 else near(x, 5) if x <= 140 else near(x, 10), 'mg')
    if 'cholesterol' in panel:
        x = Fraction(str(panel['cholesterol']))
        out['cholesterol'] = '0 mg' if x < 2 else 'less than 5 mg' if x < 5 else show(near(x, 5), 'mg')
    if 'carbs' in panel:
        x = Fraction(str(panel['carbs']))
        out['carbs'] = '0 g' if x < Fraction(1, 2) else 'less than 1 g' if x < 1 else show(near(x, 1), 'g')
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['empty panel', [{}], {}],
  ['insignificant calories', [{'calories': 4.9, 'fat': 0.4}], {'calories': '0', 'fat': '0 g'}],
  ['mid-band sodium', [{'carbs': 0.9, 'sodium': 137.5}], {'carbs': 'less than 1 g', 'sodium': '140 mg'}],
  ['regression: fat half-gram band', [{'calories': 10.75, 'carbs': 0.9, 'fat': 0.5}],
   {'calories': '10', 'carbs': 'less than 1 g', 'fat': '0.5 g'}],
  ['repair check: fat half-gram band', [{'calories': 56, 'carbs': 0.2, 'fat': 1.25, 'sodium': 198}],
   {'calories': '60', 'carbs': '0 g', 'fat': '1.5 g', 'sodium': '200 mg'}],
  ['generated control 1', [{'calories': 43.25, 'carbs': 1.5, 'sodium': 145}],
   {'calories': '45', 'carbs': '2 g', 'sodium': '150 mg'}],
  ['generated control 2', [{'calories': 65.5, 'fat': 2.75, 'sodium': 131.5}],
   {'calories': '70', 'fat': '3 g', 'sodium': '130 mg'}],
  ['generated control 3', [{'calories': 44.25, 'carbs': 30.4, 'fat': 13}],
   {'calories': '45', 'carbs': '30 g', 'fat': '13 g'}]],
 [['insignificant calories', [{'calories': 4.9, 'fat': 0.4}], {'calories': '0', 'fat': '0 g'}],
  ['mid-band sodium', [{'carbs': 0.9, 'sodium': 137.5}], {'carbs': 'less than 1 g', 'sodium': '140 mg'}],
  ['large values', [{'calories': 245, 'cholesterol': 22.5, 'fat': 12.5, 'sodium': 455}],
   {'calories': '250', 'cholesterol': '25 mg', 'fat': '13 g', 'sodium': '460 mg'}],
  ['regression: fat half-gram band', [{'calories': 49.25, 'fat': 3.5, 'sodium': 143.5}],
   {'calories': '50', 'fat': '3.5 g', 'sodium': '140 mg'}],
  ['repair check: fat half-gram band', [{'calories': 3, 'cholesterol': 5, 'fat': 1.25, 'sodium': 189.5}],
   {'calories': '0', 'cholesterol': '5 mg', 'fat': '1.5 g', 'sodium': '190 mg'}],
  ['generated control 1', [{'calories': 5.25, 'fat': 2, 'sodium': 143}],
   {'calories': '5', 'fat': '2 g', 'sodium': '140 mg'}],
  ['generated control 2', [{'calories': 0.25, 'carbs': 1, 'cholesterol': 3, 'fat': 17.75, 'sodium': 3}],
   {'calories': '0', 'carbs': '1 g', 'cholesterol': 'less than 5 mg', 'fat': '18 g', 'sodium': '0 mg'}],
  ['generated control 3', [{'calories': 45.5, 'cholesterol': 3, 'fat': 4.75, 'sodium': 7.5}],
   {'calories': '45', 'cholesterol': 'less than 5 mg', 'fat': '5 g', 'sodium': '10 mg'}]],
 [['mid-band sodium', [{'carbs': 0.9, 'sodium': 137.5}], {'carbs': 'less than 1 g', 'sodium': '140 mg'}],
  ['large values', [{'calories': 245, 'cholesterol': 22.5, 'fat': 12.5, 'sodium': 455}],
   {'calories': '250', 'cholesterol': '25 mg', 'fat': '13 g', 'sodium': '460 mg'}],
  ['small cholesterol', [{'carbs': 12.5, 'cholesterol': 3}],
   {'carbs': '13 g', 'cholesterol': 'less than 5 mg'}],
  ['regression: fat half-gram band', [{'calories': 12.5, 'cholesterol': 22.5, 'fat': 0.5, 'sodium': 120.5}],
   {'calories': '15', 'cholesterol': '25 mg', 'fat': '0.5 g', 'sodium': '120 mg'}],
  ['repair check: fat half-gram band', [{'calories': 2.5, 'fat': 2.5, 'sodium': 197.5}],
   {'calories': '0', 'fat': '2.5 g', 'sodium': '200 mg'}],
  ['generated control 1', [{'calories': 2.25, 'fat': 4, 'sodium': 7.5}],
   {'calories': '0', 'fat': '4 g', 'sodium': '10 mg'}],
  ['generated control 2', [{'calories': 270, 'carbs': 1.5, 'fat': 6, 'sodium': 3.25}],
   {'calories': '270', 'carbs': '2 g', 'fat': '6 g', 'sodium': '0 mg'}],
  ['generated control 3', [{'calories': 0, 'cholesterol': 2, 'fat': 0.4, 'sodium': 0.25}],
   {'calories': '0', 'cholesterol': 'less than 5 mg', 'fat': '0 g', 'sodium': '0 mg'}]],
 [['large values', [{'calories': 245, 'cholesterol': 22.5, 'fat': 12.5, 'sodium': 455}],
   {'calories': '250', 'cholesterol': '25 mg', 'fat': '13 g', 'sodium': '460 mg'}],
  ['small cholesterol', [{'carbs': 12.5, 'cholesterol': 3}],
   {'carbs': '13 g', 'cholesterol': 'less than 5 mg'}],
  ['empty panel', [{}], {}],
  ['regression: fat half-gram band', [{'calories': 241, 'cholesterol': 2, 'fat': 0.5, 'sodium': 142.5}],
   {'calories': '240', 'cholesterol': 'less than 5 mg', 'fat': '0.5 g', 'sodium': '140 mg'}],
  ['repair check: fat half-gram band', [{'calories': 185.5, 'cholesterol': 7.5, 'fat': 3.5, 'sodium': 122}],
   {'calories': '190', 'cholesterol': '10 mg', 'fat': '3.5 g', 'sodium': '120 mg'}],
  ['generated control 1', [{'calories': 4.6, 'fat': 10.5, 'sodium': 12.5}],
   {'calories': '0', 'fat': '11 g', 'sodium': '15 mg'}],
  ['generated control 2', [{'calories': 365.5, 'carbs': 12.5, 'cholesterol': 2, 'sodium': 3.5}],
   {'calories': '370', 'carbs': '13 g', 'cholesterol': 'less than 5 mg', 'sodium': '0 mg'}],
  ['generated control 3', [{'calories': 2.5, 'carbs': 0.9, 'fat': 18}],
   {'calories': '0', 'carbs': 'less than 1 g', 'fat': '18 g'}]],
 [['small cholesterol', [{'carbs': 12.5, 'cholesterol': 3}],
   {'carbs': '13 g', 'cholesterol': 'less than 5 mg'}],
  ['empty panel', [{}], {}],
  ['insignificant calories', [{'calories': 4.9, 'fat': 0.4}], {'calories': '0', 'fat': '0 g'}],
  ['regression: fat half-gram band', [{'calories': 56.25, 'carbs': 1.5, 'fat': 1.25}],
   {'calories': '60', 'carbs': '2 g', 'fat': '1.5 g'}],
  ['repair check: fat half-gram band', [{'calories': 156.5, 'carbs': 0.2, 'fat': 4.5, 'sodium': 132}],
   {'calories': '160', 'carbs': '0 g', 'fat': '4.5 g', 'sodium': '130 mg'}],
  ['generated control 1', [{'carbs': 1, 'fat': 5.5}], {'carbs': '1 g', 'fat': '6 g'}],
  ['generated control 2', [{'calories': 9, 'sodium': 12.5}], {'calories': '10', 'sodium': '15 mg'}],
  ['generated control 3', [{'calories': 85.5, 'carbs': 1.5, 'cholesterol': 3, 'fat': 1, 'sodium': 7}],
   {'calories': '90', 'carbs': '2 g', 'cholesterol': 'less than 5 mg', 'fat': '1 g', 'sodium': '5 mg'}]]]
for label, args, expected in fixtures[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
empty panel{}{}Passed
insignificant calories{'calories': '0', 'fat': '0 g'}{'calories': '0', 'fat': '0 g'}Passed
mid-band sodium{'carbs': 'less than 1 g', 'sodium': '140 mg'}{'carbs': 'less than 1 g', 'sodium': '140 mg'}Passed
regression: fat half-gram band{'calories': '10', 'carbs': 'less than 1 g', 'fat': '0.5 g'}{'calories': '10', 'carbs': 'less than 1 g', 'fat': '0.5 g'}Passed
repair check: fat half-gram band{'calories': '60', 'carbs': '0 g', 'fat': '1 g', 'sodium': '200 mg'}{'calories': '60', 'carbs': '0 g', 'fat': '1.5 g', 'sodium': '200 mg'}Failed
generated control 1{'calories': '45', 'carbs': '2 g', 'sodium': '150 mg'}{'calories': '45', 'carbs': '2 g', 'sodium': '150 mg'}Passed
generated control 2{'calories': '70', 'fat': '3 g', 'sodium': '130 mg'}{'calories': '70', 'fat': '3 g', 'sodium': '130 mg'}Passed
generated control 3{'calories': '45', 'carbs': '30 g', 'fat': '13 g'}{'calories': '45', 'carbs': '30 g', 'fat': '13 g'}Passed

SHA-256 / 920f3b68450b9bdd69743480d5cb26a5f19904ff408a3308e7d9790516e2c036

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json
import math
from fractions import Fraction
N = 1
observations = []
def solve(panel):
    def near(x, step):
        return math.floor(x / step + Fraction(1, 2)) * step
    def show(v, unit):
        t = format(float(v), 'g')
        return t + ' ' + unit if unit else t
    out = {}
    if 'calories' in panel:
        c = Fraction(str(panel['calories']))
        out['calories'] = show(0 if c < 5 else near(c, 5) if c <= 50 else near(c, 10), '')
    if 'fat' in panel:
        x = Fraction(str(panel['fat']))
        out['fat'] = show(0 if x < Fraction(1, 2) else near(x, Fraction(1, 2)) if x < 5 else near(x, 1), 'g')
    if 'sodium' in panel:
        x = Fraction(str(panel['sodium']))
        out['sodium'] = show(0 if x < 5 else near(x, 5) if x <= 140 else near(x, 10), 'mg')
    if 'cholesterol' in panel:
        x = Fraction(str(panel['cholesterol']))
        out['cholesterol'] = '0 mg' if x < 2 else 'less than 5 mg' if x < 5 else show(near(x, 5), 'mg')
    if 'carbs' in panel:
        x = Fraction(str(panel['carbs']))
        out['carbs'] = '0 g' if x < Fraction(1, 2) else 'less than 1 g' if x < 1 else show(near(x, 1), 'g')
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['empty panel', [{}], {}],
  ['insignificant calories', [{'calories': 4.9, 'fat': 0.4}], {'calories': '0', 'fat': '0 g'}],
  ['mid-band sodium', [{'carbs': 0.9, 'sodium': 137.5}], {'carbs': 'less than 1 g', 'sodium': '140 mg'}],
  ['regression: fat half-gram band', [{'calories': 10.75, 'carbs': 0.9, 'fat': 0.5}],
   {'calories': '10', 'carbs': 'less than 1 g', 'fat': '0.5 g'}],
  ['repair check: fat half-gram band', [{'calories': 56, 'carbs': 0.2, 'fat': 1.25, 'sodium': 198}],
   {'calories': '60', 'carbs': '0 g', 'fat': '1.5 g', 'sodium': '200 mg'}],
  ['generated control 1', [{'calories': 43.25, 'carbs': 1.5, 'sodium': 145}],
   {'calories': '45', 'carbs': '2 g', 'sodium': '150 mg'}],
  ['generated control 2', [{'calories': 65.5, 'fat': 2.75, 'sodium': 131.5}],
   {'calories': '70', 'fat': '3 g', 'sodium': '130 mg'}],
  ['generated control 3', [{'calories': 44.25, 'carbs': 30.4, 'fat': 13}],
   {'calories': '45', 'carbs': '30 g', 'fat': '13 g'}]],
 [['insignificant calories', [{'calories': 4.9, 'fat': 0.4}], {'calories': '0', 'fat': '0 g'}],
  ['mid-band sodium', [{'carbs': 0.9, 'sodium': 137.5}], {'carbs': 'less than 1 g', 'sodium': '140 mg'}],
  ['large values', [{'calories': 245, 'cholesterol': 22.5, 'fat': 12.5, 'sodium': 455}],
   {'calories': '250', 'cholesterol': '25 mg', 'fat': '13 g', 'sodium': '460 mg'}],
  ['regression: fat half-gram band', [{'calories': 49.25, 'fat': 3.5, 'sodium': 143.5}],
   {'calories': '50', 'fat': '3.5 g', 'sodium': '140 mg'}],
  ['repair check: fat half-gram band', [{'calories': 3, 'cholesterol': 5, 'fat': 1.25, 'sodium': 189.5}],
   {'calories': '0', 'cholesterol': '5 mg', 'fat': '1.5 g', 'sodium': '190 mg'}],
  ['generated control 1', [{'calories': 5.25, 'fat': 2, 'sodium': 143}],
   {'calories': '5', 'fat': '2 g', 'sodium': '140 mg'}],
  ['generated control 2', [{'calories': 0.25, 'carbs': 1, 'cholesterol': 3, 'fat': 17.75, 'sodium': 3}],
   {'calories': '0', 'carbs': '1 g', 'cholesterol': 'less than 5 mg', 'fat': '18 g', 'sodium': '0 mg'}],
  ['generated control 3', [{'calories': 45.5, 'cholesterol': 3, 'fat': 4.75, 'sodium': 7.5}],
   {'calories': '45', 'cholesterol': 'less than 5 mg', 'fat': '5 g', 'sodium': '10 mg'}]],
 [['mid-band sodium', [{'carbs': 0.9, 'sodium': 137.5}], {'carbs': 'less than 1 g', 'sodium': '140 mg'}],
  ['large values', [{'calories': 245, 'cholesterol': 22.5, 'fat': 12.5, 'sodium': 455}],
   {'calories': '250', 'cholesterol': '25 mg', 'fat': '13 g', 'sodium': '460 mg'}],
  ['small cholesterol', [{'carbs': 12.5, 'cholesterol': 3}],
   {'carbs': '13 g', 'cholesterol': 'less than 5 mg'}],
  ['regression: fat half-gram band', [{'calories': 12.5, 'cholesterol': 22.5, 'fat': 0.5, 'sodium': 120.5}],
   {'calories': '15', 'cholesterol': '25 mg', 'fat': '0.5 g', 'sodium': '120 mg'}],
  ['repair check: fat half-gram band', [{'calories': 2.5, 'fat': 2.5, 'sodium': 197.5}],
   {'calories': '0', 'fat': '2.5 g', 'sodium': '200 mg'}],
  ['generated control 1', [{'calories': 2.25, 'fat': 4, 'sodium': 7.5}],
   {'calories': '0', 'fat': '4 g', 'sodium': '10 mg'}],
  ['generated control 2', [{'calories': 270, 'carbs': 1.5, 'fat': 6, 'sodium': 3.25}],
   {'calories': '270', 'carbs': '2 g', 'fat': '6 g', 'sodium': '0 mg'}],
  ['generated control 3', [{'calories': 0, 'cholesterol': 2, 'fat': 0.4, 'sodium': 0.25}],
   {'calories': '0', 'cholesterol': 'less than 5 mg', 'fat': '0 g', 'sodium': '0 mg'}]],
 [['large values', [{'calories': 245, 'cholesterol': 22.5, 'fat': 12.5, 'sodium': 455}],
   {'calories': '250', 'cholesterol': '25 mg', 'fat': '13 g', 'sodium': '460 mg'}],
  ['small cholesterol', [{'carbs': 12.5, 'cholesterol': 3}],
   {'carbs': '13 g', 'cholesterol': 'less than 5 mg'}],
  ['empty panel', [{}], {}],
  ['regression: fat half-gram band', [{'calories': 241, 'cholesterol': 2, 'fat': 0.5, 'sodium': 142.5}],
   {'calories': '240', 'cholesterol': 'less than 5 mg', 'fat': '0.5 g', 'sodium': '140 mg'}],
  ['repair check: fat half-gram band', [{'calories': 185.5, 'cholesterol': 7.5, 'fat': 3.5, 'sodium': 122}],
   {'calories': '190', 'cholesterol': '10 mg', 'fat': '3.5 g', 'sodium': '120 mg'}],
  ['generated control 1', [{'calories': 4.6, 'fat': 10.5, 'sodium': 12.5}],
   {'calories': '0', 'fat': '11 g', 'sodium': '15 mg'}],
  ['generated control 2', [{'calories': 365.5, 'carbs': 12.5, 'cholesterol': 2, 'sodium': 3.5}],
   {'calories': '370', 'carbs': '13 g', 'cholesterol': 'less than 5 mg', 'sodium': '0 mg'}],
  ['generated control 3', [{'calories': 2.5, 'carbs': 0.9, 'fat': 18}],
   {'calories': '0', 'carbs': 'less than 1 g', 'fat': '18 g'}]],
 [['small cholesterol', [{'carbs': 12.5, 'cholesterol': 3}],
   {'carbs': '13 g', 'cholesterol': 'less than 5 mg'}],
  ['empty panel', [{}], {}],
  ['insignificant calories', [{'calories': 4.9, 'fat': 0.4}], {'calories': '0', 'fat': '0 g'}],
  ['regression: fat half-gram band', [{'calories': 56.25, 'carbs': 1.5, 'fat': 1.25}],
   {'calories': '60', 'carbs': '2 g', 'fat': '1.5 g'}],
  ['repair check: fat half-gram band', [{'calories': 156.5, 'carbs': 0.2, 'fat': 4.5, 'sodium': 132}],
   {'calories': '160', 'carbs': '0 g', 'fat': '4.5 g', 'sodium': '130 mg'}],
  ['generated control 1', [{'carbs': 1, 'fat': 5.5}], {'carbs': '1 g', 'fat': '6 g'}],
  ['generated control 2', [{'calories': 9, 'sodium': 12.5}], {'calories': '10', 'sodium': '15 mg'}],
  ['generated control 3', [{'calories': 85.5, 'carbs': 1.5, 'cholesterol': 3, 'fat': 1, 'sodium': 7}],
   {'calories': '90', 'carbs': '2 g', 'cholesterol': 'less than 5 mg', 'fat': '1 g', 'sodium': '5 mg'}]]]
for label, args, expected in fixtures[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
empty panel{}{}Passed
insignificant calories{'calories': '0', 'fat': '0 g'}{'calories': '0', 'fat': '0 g'}Passed
mid-band sodium{'carbs': 'less than 1 g', 'sodium': '140 mg'}{'carbs': 'less than 1 g', 'sodium': '140 mg'}Passed
regression: fat half-gram band{'calories': '10', 'carbs': 'less than 1 g', 'fat': '0.5 g'}{'calories': '10', 'carbs': 'less than 1 g', 'fat': '0.5 g'}Passed
repair check: fat half-gram band{'calories': '60', 'carbs': '0 g', 'fat': '1.5 g', 'sodium': '200 mg'}{'calories': '60', 'carbs': '0 g', 'fat': '1.5 g', 'sodium': '200 mg'}Passed
generated control 1{'calories': '45', 'carbs': '2 g', 'sodium': '150 mg'}{'calories': '45', 'carbs': '2 g', 'sodium': '150 mg'}Passed
generated control 2{'calories': '70', 'fat': '3 g', 'sodium': '130 mg'}{'calories': '70', 'fat': '3 g', 'sodium': '130 mg'}Passed
generated control 3{'calories': '45', 'carbs': '30 g', 'fat': '13 g'}{'calories': '45', 'carbs': '30 g', 'fat': '13 g'}Passed

SHA-256 / 2fe68ffdc96c16e8d74bfb20de833edc661d34bdf1085a9bd7c4a5d2a1f2c625

Verification & scope

A deterministic toy contract stated in full here; it is a bounded teaching model, not an authoritative reference or standards implementation. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:52:26.833854+00:00.

Case digest / 50cc023e041ea97648d1e877e36ec61b896377335d1c279eaefb956fad3cbe68