[
  {"id": "168ee1fead32400b-payroll", "kind": "payroll"},
  {"id": "168ee1fead32400b-contract", "kind": "contract"},
  {"id": "168ee1fead32400b-amendment", "kind": "amendment"}
]

{
  "kind": "payroll",
  "record": {"gross_pay": "599.56", "payroll_month": "2026-12", "allowed_deduction": "68.60"}
}

{
  "kind": "contract",
  "gross_pay": "1019.55"
}

{
  "kind": "amendment",
  "gross_pay": "599.56",
  "approved": true,
  "effective_month": "2026-01"
}

The payroll record shows gross_pay 599.56 for 2026-12, while the contract says 1019.55 — a potential conflict. The amendment (599.56, approved, effective 2026-01) appears to resolve it under R9. Now I need the reference row for 2026-12.

The payroll record:
- gross_pay: 599.56
- payroll_month: 2026-12
- allowed_deduction: 68.60

Contract gross_pay: 1019.55 — differs from payroll gross_pay 599.56. So there's a potential conflict under R7.4.

Amendment: gross_pay 599.56, approved: true, effective_month: 2026-01. Effective month 2026-01 ≤ payroll month 2026-12, approved, and amount equals payroll record's gross pay (599.56). So the amendment resolves the conflict under R9.

Now I need the reference row for 2026-12. Only 2026 is covered. The reference schedule is available via lookup_reference. 2026-12 is in the second half of the year presumably. Let me check lookup_reference for second-half (and maybe first-half to be thorough, but December is second half). Let me call lookup_reference with "second-half".

Actually, the rules say "Read first-half or second-half payroll reference rates and effective months." December 2026 would be second-half. Let me look up second-half. I could also look up first-half to confirm boundaries, but December is clearly second half. To be safe, I could fetch both in parallel since they're independent. That seems reasonable to confirm which row covers 2026-12.

Then compute:
- contribution = rate * min(gross, cap)
- allowed_deduction = 68.60, must not exceed deduction cap or gross - contribution
- taxable_pay = gross - contribution - deduction
- income tax: progressive brackets from selected row: tax-free amount, middle rate up to upper boundary, upper rate above.
- net = gross - contribution - deduction - tax.

Let me fetch both reference halves in parallel.

{
  "reference": "first-half",
  "months": ["2026-01", "2026-06"],
  "rate": "0.06",
  "cap": "4500.00",
  "deduction": "400.00",
  "free": "900.00",
  "upper": "3000.00",
  "middle_rate": "0.14",
  "upper_rate": "0.22"
}

{
  "reference": "second-half",
  "months": ["2026-07", "2026-12"],
  "rate": "0.06",
  "cap": "4000.00",
  "deduction": "400.00",
  "free": "900.00",
  "upper": "2800.00",
  "middle_rate": "0.14",
  "upper_rate": "0.20"
}

The 2026-12 row is the second-half schedule: rate 0.06, cap 4000.00, deduction cap 400.00, free 900.00, upper 2800.00, middle_rate 0.14, upper_rate 0.20. Now the exact arithmetic:

2026-12 falls in the second-half row (2026-07 through 2026-12):
- rate: 0.06
- cap: 4000.00
- deduction cap: 400.00
- free: 900.00
- upper: 2800.00
- middle_rate: 0.14
- upper_rate: 0.20

Now compute:

1. Employee contribution (R3): rate * min(gross, cap) = 0.06 * min(599.56, 4000.00) = 0.06 * 599.56 = 35.9736 → round to 35.97.

2. Allowed deduction check (R4): allowed_deduction = 68.60. Must not exceed deduction cap (400.00) or gross pay minus rounded contribution (599.56 - 35.97 = 563.59). 68.60 ≤ both. OK.

3. Taxable pay (R4): gross - contribution - deduction = 599.56 - 35.97 - 68.60 = 494.99.

4. Income tax (R5): taxable 494.99 ≤ free 900.00, so tax = 0.00.

5. Net pay (R6): 599.56 - 35.97 - 68.60 - 0.00 = 494.99.

Let me verify with calculate.

{
  "results": {"contribution_base": "599.56", "employee_contribution": "35.97", "deduction_cap_check": "400.00", "taxable_pay": "494.99", "tax_free_portion": "494.99", "middle_portion": "0", "upper_portion": "0", "income_tax": "0.00", "net_pay": "494.99"}
}

All checks pass. The contract/payroll conflict (1019.55 vs 599.56) is resolved by the approved amendment effective 2026-01 (≤ 2026-12) whose amount equals the payroll record's gross pay under R9.

```json
{
  "decision": "calculate",
  "currency": "LCR",
  "gross_pay": "599.56",
  "employee_contribution": "35.97",
  "allowed_deduction": "68.60",
  "taxable_pay": "494.99",
  "income_tax": "0.00",
  "net_pay": "494.99",
  "clauses": ["R1", "R2", "R3", "R4", "R5", "R6", "R9"],
  "explanation": "Payroll month 2026-12 selects the second-half reference row (rate 0.06, cap 4000.00, deduction cap 400.00, free 900.00, upper 2800.00, middle 0.14, upper 0.20). Contract gross_pay 1019.55 conflicts with the payroll record, but the approved amendment (599.56, effective 2026-01, matching amount) resolves it under R9. Contribution = 0.06 x min(599.56, 4000.00) = 35.97. Allowed deduction 68.60 is within the 400.00 cap and available pay (563.59). Taxable pay = 599.56 - 35.97 - 68.60 = 494.99, entirely within the 900.00 tax-free band, so income tax is 0.00. Net pay = 599.56 - 35.97 - 68.60 - 0.00 = 494.99."
}
```

All checks pass:
- Employee contribution: 0.06 × 599.56 = 35.9736 → 35.97 (R3)
- Allowed deduction 68.60 ≤ 400.00 cap and ≤ 563.59 available pay (R4)
- Taxable pay: 599.56 − 35.97 − 68.60 = 494.99 (R4)
- Income tax: 494.99 ≤ 900.00 free → 0.00 (R5)
- Net pay: 599.56 − 35.97 − 68.60 − 0.00 = 494.99 (R6)

Conflict resolution: contract gross_pay 1019.55 differs from payroll 599.56, but the amendment (599.56, approved: true, effective 2026-01 ≤ 2026-12, amount equals payroll gross) resolves it under R9. So I cite R1–R6 and R9.

Answer JSON:
{
  "decision": "calculate",
  "currency": "LCR",
  "gross_pay": "599.56",
  "employee_contribution": "35.97",
  "allowed_deduction": "68.60",
  "taxable_pay": "494.99",
  "income_tax": "0.00",
  "net_pay": "494.99",
  "clauses": ["R1", "R2", "R3", "R4", "R5", "R6", "R9"]
}

Maybe include an explanation about the amendment resolving the conflict. The optional explanation string is permitted. I'll add a brief one.

[
  {"id": "168ee1fead32400b-payroll", "kind": "payroll"},
  {"id": "168ee1fead32400b-contract", "kind": "contract"},
  {"id": "168ee1fead32400b-amendment", "kind": "amendment"}
]

{
  "kind": "payroll",
  "record": {"gross_pay": "599.56", "payroll_month": "2026-12", "allowed_deduction": "68.60"}
}

{
  "kind": "contract",
  "gross_pay": "1019.55"
}

{
  "kind": "amendment",
  "gross_pay": "599.56",
  "approved": true,
  "effective_month": "2026-01"
}

The payroll record shows gross_pay 599.56 for 2026-12, but the contract states 1019.55 — a conflict. The amendment (599.56, approved, effective 2026-01) appears to resolve it under R9. Now I need the reference row for December 2026 (second half of the year).

Payroll record: gross_pay = 599.56, payroll_month = 2026-12, allowed_deduction = 68.60.

Contract gross_pay = 1019.55 — differs from payroll gross_pay 599.56. So there's a conflict (R7 step 4). But there's an amendment: gross_pay = 599.56, approved = true, effective_month = 2026-01, which is no later than payroll month 2026-12, and its amount equals the payroll record's gross pay (599.56). So under R9, the amendment resolves the conflict. Gross pay = 599.56.

Now I need the reference row for 2026-12. Only 2026 is covered. Which half does December fall in? First-half and second-half — likely first half is Jan–Jun, second half is Jul–Dec. December is in the second half. Let me look up the second-half reference.

Also, need to check the allowed deduction: 68.60 must not exceed the deduction cap or gross pay minus rounded employee contribution.

Let me get the reference row first.

{
  "reference": "second-half",
  "months": ["2026-07", "2026-12"],
  "rate": "0.06",
  "cap": "4000.00",
  "deduction": "400.00",
  "free": "900.00",
  "upper": "2800.00",
  "middle_rate": "0.14",
  "upper_rate": "0.20"
}

The second-half row covers 2026-07 through 2026-12, so it applies to 2026-12. Now let me compute the payroll with exact decimal arithmetic.

Second-half row (covers 2026-07 through 2026-12):
- rate: 0.06
- cap: 4000.00
- deduction cap: 400.00
- free: 900.00
- upper: 2800.00
- middle_rate: 0.14
- upper_rate: 0.20

Now compute:
1. Employee contribution = round(min(4000.00, 599.56) * 0.06, 2) = round(599.56 * 0.06, 2) = round(35.9736, 2) = 35.97.
2. Allowed deduction check: 68.60 ≤ 400.00 (cap) and ≤ gross - contribution = 599.56 - 35.97 = 563.59. OK.
3. Taxable pay = 599.56 - 35.97 - 68.60 = 494.99.
4. Income tax: taxable 494.99 ≤ free 900.00, so tax = 0.00.
5. Net pay = 599.56 - 35.97 - 68.60 - 0.00 = 494.99.

Let me verify with the calculator.

{
  "results": {"contribution": "35.97", "deduction_check": "68.60", "available": "563.59", "taxable": "494.99", "tax_free_portion": "494.99", "middle_portion": "0.00", "upper_portion": "0.00", "income_tax": "0.00", "net_pay": "494.99"}
}

{
  "decision": "calculate",
  "currency": "LCR",
  "gross_pay": "599.56",
  "employee_contribution": "35.97",
  "allowed_deduction": "68.60",
  "taxable_pay": "494.99",
  "income_tax": "0.00",
  "net_pay": "494.99",
  "clauses": ["R1", "R2", "R3", "R4", "R5", "R9"],
  "explanation": "Contract gross pay (1019.55) conflicts with the payroll record (599.56), but the amendment is approved, effective 2026-01 (no later than payroll month 2026-12), and equals the payroll gross pay, so it resolves the conflict under R9. The second-half reference row (2026-07 to 2026-12) applies: contribution = round(min(4000.00, 599.56) \u00d7 0.06, 2) = 35.97. The allowed deduction 68.60 is within both the 400.00 deduction cap and gross pay minus contribution (563.59), so it is valid under R4. Taxable pay = 599.56 \u2212 35.97 \u2212 68.60 = 494.99. Taxable pay is entirely within the 900.00 tax-free band, so income tax is 0.00 under R5. Net pay = 599.56 \u2212 35.97 \u2212 68.60 \u2212 0.00 = 494.99."
}

All checks pass:
- Employee contribution: 35.97 (min(4000.00, 599.56) * 0.06 = 35.9736 → 35.97)
- Allowed deduction 68.60 ≤ 400.00 cap and ≤ 563.59 (gross − contribution). Valid.
- Taxable pay: 494.99
- Income tax: taxable ≤ 900.00 free → 0.00
- Net pay: 599.56 − 35.97 − 68.60 − 0.00 = 494.99

The amendment resolves the contract conflict: approved, effective 2026-01 ≤ 2026-12, amount 599.56 equals payroll gross pay. So cite R9 as well.

Answer JSON with decision: calculate, currency LCR, fields, clauses R1, R2, R3, R4, R5, R9.

[
  {"id": "168ee1fead32400b-payroll", "kind": "payroll"},
  {"id": "168ee1fead32400b-contract", "kind": "contract"},
  {"id": "168ee1fead32400b-amendment", "kind": "amendment"}
]

{
  "reference": "first-half",
  "months": ["2026-01", "2026-06"],
  "rate": "0.06",
  "cap": "4500.00",
  "deduction": "400.00",
  "free": "900.00",
  "upper": "3000.00",
  "middle_rate": "0.14",
  "upper_rate": "0.22"
}

{
  "reference": "second-half",
  "months": ["2026-07", "2026-12"],
  "rate": "0.06",
  "cap": "4000.00",
  "deduction": "400.00",
  "free": "900.00",
  "upper": "2800.00",
  "middle_rate": "0.14",
  "upper_rate": "0.20"
}

{
  "kind": "payroll",
  "record": {"gross_pay": "599.56", "payroll_month": "2026-12", "allowed_deduction": "68.60"}
}

{
  "kind": "contract",
  "gross_pay": "1019.55"
}

{
  "kind": "amendment",
  "gross_pay": "599.56",
  "approved": true,
  "effective_month": "2026-01"
}

The payroll month is 2026-12, so the second-half row applies (rate 0.06, cap 4000.00, deduction cap 400.00, free 900.00). The contract (1019.55) conflicts with the payroll gross pay (599.56), but the amendment is approved, effective 2026-01 (no later than 2026-12), and its amount equals the payroll record's gross pay — so it resolves the conflict under R9. Let me compute exactly.

Payroll month: 2026-12 → second-half row: rate 0.06, cap 4000.00, deduction 400.00, free 900.00, upper 2800.00, middle_rate 0.14, upper_rate 0.20.

Gross pay: 599.56. Contract gross pay is 1019.55, which differs from payroll gross pay 599.56. Amendment: gross_pay 599.56, approved true, effective_month 2026-01 ≤ 2026-12, and amount equals payroll record's gross pay (599.56 = 599.56). So the conflict is resolved under R9. So we proceed with gross_pay = 599.56.

Employee contribution: min(599.56, 4000.00) * 0.06 = 599.56 * 0.06 = 35.9736 → round to 35.97.

Allowed deduction: 68.60. Check: must not exceed deduction cap 400.00 — OK. Must not exceed gross pay minus rounded contribution: 599.56 - 35.97 = 563.59. 68.60 ≤ 563.59 — OK.

Taxable pay: 599.56 - 35.97 - 68.60 = 494.99.

Income tax: taxable pay 494.99 ≤ free 900.00, so tax = 0.00.

Net pay: 599.56 - 35.97 - 68.60 - 0.00 = 494.99.

Let me verify with calculate.

{
  "results": {"contribution_raw": "35.9736", "contribution": "35.97", "available": "563.59", "taxable": "494.99", "tax": "0.00", "net": "494.99"}
}

{
  "decision": "calculate",
  "currency": "LCR",
  "gross_pay": "599.56",
  "employee_contribution": "35.97",
  "allowed_deduction": "68.60",
  "taxable_pay": "494.99",
  "income_tax": "0.00",
  "net_pay": "494.99",
  "clauses": ["R1", "R2", "R3", "R4", "R5", "R6", "R9"],
  "explanation": "Payroll month 2026-12 selects the second-half reference row (rate 0.06, cap 4000.00, deduction cap 400.00, tax-free 900.00). Contract gross pay (1019.55) conflicted with the payroll record (599.56), but the approved amendment effective 2026-01 matches the payroll gross pay, resolving the conflict under R9. Contribution = 0.06 \u00d7 min(599.56, 4000.00) = 35.9736 \u2192 35.97. Allowed deduction 68.60 is within the 400.00 cap and within available pay (599.56 \u2212 35.97 = 563.59). Taxable pay = 599.56 \u2212 35.97 \u2212 68.60 = 494.99, which is below the 900.00 tax-free amount, so income tax is 0.00. Net pay = 599.56 \u2212 35.97 \u2212 68.60 \u2212 0.00 = 494.99."
}

All checks pass:
- Contribution: 35.97 (0.06 × min(599.56, 4000.00) = 35.9736 → 35.97)
- Allowed deduction 68.60 ≤ cap 400.00 and ≤ available 563.59 (R4)
- Taxable pay: 494.99
- Tax: 0.00 (below free 900.00)
- Net: 494.99

Citations: R1 (row selection), R2 (rounding), R3 (contribution), R4 (deduction/taxable), R5 (tax), R6 (net/answer), R9 (amendment resolves conflict).