Let me work through this payroll case.

Payroll month: 2026-09 → second-half row of the authoritative case schedule:
- rate: 0.04
- cap: 4500.00
- deduction cap: 400.00
- tax-free: 1000.00
- upper begins: 3000.00
- middle rate: 0.12
- upper rate: 0.22

Gross pay: 5662.30 (payroll record). Contract says 6025.51, but amendment: gross_pay 5662.30, approved true, effective_month 2026-03 ≤ 2026-09, amount equals payroll record's gross pay (5662.30). So the amendment resolves the contract conflict under R9. So no clarification needed; calculate.

Employee contribution: rate × min(gross, cap) = 0.04 × min(5662.30, 4500.00) = 0.04 × 4500.00 = 180.00.

Allowed deduction check: must not exceed deduction cap (400.00) and not exceed gross pay minus rounded employee contribution = 5662.30 − 180.00 = 5482.30. Allowed deduction 169.02 is fine.

Taxable pay = 5662.30 − 180.00 − 169.02 = 5313.28.

Income tax (marginal):
- First 1000.00: 0 tax.
- 1000.00 to 3000.00: 2000.00 × 0.12 = 240.00.
- Above 3000.00: 5313.28 − 3000.00 = 2313.28 × 0.22 = 508.9216 → keep unrounded until sum. Sum = 240 + 508.9216 = 748.9216 → round to 748.92.

Net pay = 5662.30 − 180.00 − 169.02 − 748.92 = 4664.36.

Check: 5662.30 − 180.00 = 5482.30; − 169.02 = 5313.28; − 748.92 = 4664.36.

Fields:
- decision: "calculate"
- currency: "LCR"
- gross_pay: "5662.30"
- employee_contribution: "180.00"
- allowed_deduction: "169.02"
- taxable_pay: "5313.28"
- income_tax: "748.92"
- net_pay: "4664.36"

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

Do not include input-only fields like payroll_month, contract_gross_pay, amendment. Include clauses.

Let me work through this payroll case.

Inputs:
- Payroll record: gross_pay = 5662.30, payroll_month = 2026-09, allowed_deduction = 169.02
- Contract gross_pay = 6025.51
- Amendment: gross_pay = 5662.30, approved = true, effective_month = 2026-03

Reference schedule (authoritative, replaces defaults):
- Second-half (2026-07 through 2026-12): rate = 0.04, cap = 4500.00, deduction = 400.00, free = 1000.00, upper = 3000.00, middle_rate = 0.12, upper_rate = 0.22

Payroll month 2026-09 → second-half row.

Check R7 order:
1. gross_pay present: 5662.30 ✓
2. payroll_month present: 2026-09 ✓
3. Month covered: 2026-09 in second-half ✓
4. Contract conflict: contract gross_pay = 6025.51 differs from payroll gross_pay = 5662.30. Amendment present: approved = true, effective_month 2026-03 ≤ 2026-09, amount 5662.30 equals payroll gross_pay 5662.30. So conflict is resolved under R9. Cite R9.

Calculate:
- Employee contribution: rate 0.04 × min(5662.30, 4500.00) = 0.04 × 4500.00 = 180.00
- Allowed deduction check: 169.02 ≤ deduction cap 400.00 ✓; must not exceed gross pay minus contribution: 5662.30 − 180.00 = 5482.30; 169.02 ≤ 5482.30 ✓
- Taxable pay: 5662.30 − 180.00 − 169.02 = 5313.28
- Income tax (second-half: free = 1000.00, upper = 3000.00, middle_rate = 0.12, upper_rate = 0.22):
  - Portion up to 1000.00: untaxed
  - 1000.00 to 3000.00: 2000.00 × 0.12 = 240.00
  - Above 3000.00: 5313.28 − 3000.00 = 2313.28 × 0.22 = 508.9216
  - Total tax = 240.00 + 508.9216 = 748.9216 → round to 748.92
- Net pay: 5662.30 − 180.00 − 169.02 − 748.92 = 4564.36

Check: 5662.30 − 180.00 = 5482.30; 5482.30 − 169.02 = 5313.28; 5313.28 − 748.92 = 4564.36. ✓

Answer fields:
- decision: "calculate"
- currency: "LCR"
- gross_pay: "5662.30"
- employee_contribution: "180.00"
- allowed_deduction: "169.02"
- taxable_pay: "5313.28"
- income_tax: "748.92"
- net_pay: "4564.36"
- clauses: R1, R2, R3, R4, R5, R6, R9

The amendment was needed to resolve the conflict, so cite R9 (Calculated answers cite R1 through R6, and also R9 only when an amendment is needed to resolve a conflict).

Maybe add explanation about the schedule being used and amendment resolving conflict.

Let me work through this payroll record.

Payroll month: 2026-09 → second-half row of the case schedule: rate 0.04, cap 4500.00, deduction cap 400.00, free 1000.00, upper 3000.00, middle_rate 0.12, upper_rate 0.22.

Gross pay: 5662.30. Contract gross pay: 6025.51. Conflict? Amendment present: gross_pay 5662.30, approved true, effective_month 2026-03 (no later than 2026-09), and amount equals payroll record's gross pay (5662.30). So the amendment resolves the conflict under R9. Cite R7 and... wait, R7 item 4: conflict resolved under R9 via approved amendment → calculate. Calculated answers cite R1 through R6, and also R9 when amendment resolves conflict.

Employee contribution: 0.04 × min(5662.30, 4500.00) = 0.04 × 4500.00 = 180.00.

Allowed deduction: 169.02. Check: ≤ 400.00 cap, and ≤ gross pay minus contribution = 5662.30 − 180.00 = 5482.30. OK.

Taxable pay: 5662.30 − 180.00 − 169.02 = 5313.28.

Income tax: free up to 1000.00 → 0. Middle: (3000.00 − 1000.00) × 0.12 = 2000.00 × 0.12 = 240.00. Upper: (5313.28 − 3000.00) × 0.22 = 2313.28 × 0.22 = 508.9216 → sum = 240.00 + 508.9216 = 748.9216 → round half up 748.92.

Net pay: 5662.30 − 180.00 − 169.02 − 748.92 = 4564.36.

Check: 5662.30 − 180.00 = 5482.30; − 169.02 = 5313.28; − 748.92 = 4564.36. Yes.

Output JSON:
{
  "decision": "calculate",
  "currency": "LCR",
  "gross_pay": "5662.30",
  "employee_contribution": "180.00",
  "allowed_deduction": "169.02",
  "taxable_pay": "5313.28",
  "income_tax": "748.92",
  "net_pay": "4564.36",
  "clauses": ["R1", "R2", "R3", "R4", "R5", "R6", "R9"]
}

Maybe include an explanation. The rules say confirmation no extra fields beyond allowed ones plus explanation optional. I'll include a brief explanation.