Let me start by listing the documents to see what inputs we have.

Let me read all three documents in parallel.

Let me analyze:

- Payroll record: gross_pay = 4188.34, payroll_month = 2026-04, allowed_deduction = 161.97
- Contract: gross_pay = 4163.34
- Amendment: gross_pay = 4218.34, effective_month = 2026-02, approved = true

R7 check order:
1. Missing gross_pay? No, present (4188.34).
2. Missing payroll_month? No, present (2026-04).
3. Month without reference row? 2026-04 is in 2026, which is covered. I need to look up the reference to get the second-half row (April is in the second half presumably). Let me check lookup_reference.
4. Contract gross_pay (4163.34) differs from payroll gross_pay (4188.34). Amendment present: approved = true, effective_month = 2026-02 ≤ 2026-04. But the amendment amount (4218.34) must equal the payroll record's gross pay (4188.34) to resolve the conflict. 4218.34 ≠ 4188.34, so the amendment does NOT resolve the conflict. Therefore decision: clarify, reason_code: CONFLICTING_GROSS_PAY, citing R7 and R9.

Wait — but the order of checks: step 3 (month without reference row) comes before step 4 (conflicting gross pay). The month 2026-04 is covered (only 2026 is covered). So we proceed to step 4. The conflict is unresolved because the amendment amount doesn't match the payroll record's gross pay.

Actually, do I even need to look up the reference? The conflict check happens before any calculation. The month is covered by reference rows (2026 is covered, and April should be in one of the halves). Since the conflict is unresolved, we return clarify without calculated monetary fields.

Hmm, but should I verify the month has a reference row? The rule says "Only 2026 is covered. Dates outside 2026 require clarification under R7." 2026-04 is within 2026, so it's covered. I don't strictly need to look up the reference to determine this, but it's prudent to confirm the row exists. Actually, the lookup_reference tool gives first-half and second-half rows. April 2026 would be in the second half (months 7-12? or 1-6 first half, 7-12 second half?). Let me think — "first-half" and "second-half" of the year presumably. April would be first half. But it doesn't matter for the clarify decision.

Actually, since the conflict check (step 4) comes after step 3, and step 3 requires confirming the month has a reference row, I could look up the reference to confirm. But the outcome is a clarify regardless. Let me be thorough and check the reference for first half to confirm April 2026 has a row. Actually, the key blocker is the conflicting gross pay. The month is covered per R1 ("Only 2026 is covered"), so 2026-04 has a reference row. I could do a lookup to be safe.

Let me do lookup_reference for first-half to confirm April is covered. Actually, since the decision is clarify due to conflicting gross pay, and R7 says "For these cases do not return calculated monetary fields," I don't need the reference values. But confirming the month is covered matters for the ordering: if the month had no reference row, I'd return NO_APPLICABLE_REFERENCE instead. Since 2026-04 is in 2026, it's covered. I'll do a quick lookup to confirm the row exists for April.

Let me check first-half (Jan-Jun presumably includes April).

Actually, let me just call lookup_reference("first-half") to confirm.

Then the answer:

{
  "decision": "clarify",
  "reason_code": "CONFLICTING_GROSS_PAY",
  "clauses": ["R7", "R9"],
  "explanation": "..."
}

The explanation should name the unresolved blocker: contract gross_pay 4163.34 differs from payroll gross_pay 4188.34; the approved amendment effective 2026-02 has amount 4218.34, which does not equal the payroll record's gross pay 4188.34, so under R9 it does not resolve the conflict. Ask for resolution (e.g., an approved amendment matching 4188.34 or corrected records).

Let me verify the amendment conditions under R9:
- approved: true ✓
- effective_month 2026-02 ≤ payroll month 2026-04 ✓
- amount equals payroll record's gross pay: 4218.34 vs 4188.34 ✗

So it does not resolve. Clarify with CONFLICTING_GROSS_PAY, citing R7 and R9.

Let me do the lookup_reference call to confirm April 2026 has a reference row (so the blocker is truly the conflict, not a missing row).

The first-half covers 2026-01 through 2026-06, which includes 2026-04. So the month has a reference row — no NO_APPLICABLE_REFERENCE issue.

Now the conflict check: contract gross_pay 4163.34 ≠ payroll gross_pay 4188.34. The amendment is approved and effective 2026-02 (≤ 2026-04), but its amount 4218.34 ≠ payroll gross_pay 4188.34. Under R9, a different-amount amendment does not resolve the conflict. So decision: clarify, reason_code: CONFLICTING_GROSS_PAY, citing R7 and R9.

No calculated monetary fields. Include explanation naming the blocker and asking for resolution.

Let me start by listing the documents to see what's in this case.

There's a payroll, contract, and amendment. Let me read all three documents.

Let me analyze:

- Payroll: gross_pay = 4188.34, payroll_month = 2026-04, allowed_deduction = 161.97
- Contract: gross_pay = 4163.34 (differs from payroll gross_pay 4188.34)
- Amendment: gross_pay = 4218.34, effective_month = 2026-02, approved = true

R9: An amendment resolves a contract conflict only if it is approved (yes), its effective month is no later than the payroll month (2026-02 ≤ 2026-04, yes), and its amount equals the payroll record's gross pay (4218.34 vs 4188.34 — NO, they differ). So the amendment does NOT resolve the conflict.

R7.4: If optional contract_gross_pay is present and differs from gross_pay, neither source takes precedence unless an approved amendment resolves it under R9. The amendment does not resolve it (different amount). So decision: "clarify", reason_code: "CONFLICTING_GROSS_PAY", citing R7 and R9.

Wait — but should I check the month first? R7 order:
1. Missing gross_pay — present.
2. Missing payroll_month — present.
3. Month without a reference row — 2026-04 is in 2026, which is covered. So there is a reference row. But I don't need to look it up since the conflict resolves to clarify anyway. Actually, the order says check conflicting inputs in this order: 1, 2, 3, 4. Month 2026-04 is covered (only 2026 is covered), so no NO_APPLICABLE_REFERENCE issue. Then step 4: contract_gross_pay present (4163.34) differs from gross_pay (4188.34). Amendment is approved and effective 2026-02 ≤ 2026-04, but amount 4218.34 ≠ 4188.34, so it does not resolve. Return clarify with CONFLICTING_GROSS_PAY.

For clarification, do not return calculated monetary fields. "Missing required values include explicit null." Hmm — for clarification, the fields are decision, reason_code, clauses, and optional explanation. The R7 text says "For these cases do not return calculated monetary fields. Missing required values include explicit null." In this case, no required values are missing — the conflict is the issue. So I don't need to include null fields. The answer format for clarify: decision, reason_code, clauses, optional explanation.

Clauses: R7 and R9 (unresolved contract conflicts cite R7 and R9).

No need to call lookup_reference or calculate since we're clarifying. Actually, should I verify the reference row exists for 2026-04? Only 2026 is covered per R1, so 2026-04 is covered. The conflict check happens at step 4, after step 3. Since the month is covered, step 3 passes, and step 4 triggers clarify.

The answer: {"decision": "clarify", "reason_code": "CONFLICTING_GROSS_PAY", "clauses": ["R7", "R9"], "explanation": "..."}

Explanation: The contract gross pay (4163.34) differs from the payroll record's gross pay (4188.34). The approved amendment effective 2026-02 does not resolve the conflict because its amount (4218.34) does not equal the payroll record's gross pay (4188.34). Under R7.4 and R9, neither source takes precedence; please provide an approved amendment matching the payroll gross pay or a corrected record.

Money must be strings with two decimal places — but for clarify, no monetary fields are returned. The explanation mentions values; that's fine as prose.

Return one JSON object without Markdown fences.

Let me start by listing documents and reading the case inputs. I also need to determine the payroll month to select the reference row. Let me first list documents.

There's a payroll record, a contract, and an amendment. Let me read all three documents in parallel.

Payroll record: gross_pay = 4188.34, payroll_month = 2026-04, allowed_deduction = 161.97.
Contract gross_pay = 4163.34 — differs from payroll gross_pay (4188.34).
Amendment: gross_pay = 4218.34, effective_month = 2026-02, approved = true.

R9: An amendment resolves a contract conflict only if it is approved, its effective month is no later than the payroll month, and its amount equals the payroll record's gross pay. Here the amendment amount (4218.34) does NOT equal the payroll record's gross pay (4188.34). So the amendment does not resolve the conflict.

Per R7 item 4: If optional contract_gross_pay is present and differs from gross_pay, neither source takes precedence unless an approved amendment resolves it under R9. Otherwise return decision: "clarify" and reason_code: "CONFLICTING_GROSS_PAY", citing R7 and R9.

Wait — but the amendment's amount differs from both the payroll gross and the contract gross. The amendment doesn't resolve. So the conflict between contract (4163.34) and payroll (4188.34) remains unresolved → clarify with CONFLICTING_GROSS_PAY.

Hmm, but let me double check: is the amendment intended to resolve the conflict? The amendment amount is 4218.34, which differs from payroll gross 4188.34. So it does not equal the payroll record's gross pay → doesn't resolve. Also it doesn't equal the contract amount either. So no resolution.

Therefore: decision "clarify", reason_code "CONFLICTING_GROSS_PAY", clauses R7 and R9.

Per R7: "For these cases do not return calculated monetary fields. Missing required values include explicit null. Do not guess a value or substitute zero."

The answer format: clarify uses decision, reason_code, clauses. Optional explanation string permitted. Include a short explanation naming the unresolved blocker and asking for its resolution.

No monetary fields should be returned for clarify. Also "Missing required values include explicit null" — but here gross_pay is present; the issue is conflict. The clarify answer fields are decision, reason_code, clauses. I'll add an explanation.

Do I need lookup_reference? No — the conflict blocks calculation before reference selection matters. Actually, the conflict check happens in R7 order: item 4 comes after checking month coverage. The month 2026-04 is in 2026, so covered. But the conflict is unresolved, so clarify. I don't need the reference table since no calculation occurs. But should I verify the month has a reference row? The conflict check is item 4 after item 3 (month without reference row). 2026-04 is covered by 2026 rules (only 2026 is covered). So no NO_APPLICABLE_REFERENCE issue. I could optionally call lookup_reference to confirm 2026-04 is covered, but the rulebook says only 2026 is covered, and 2026-04 is in 2026. It's fine. Actually, to be thorough, I could call lookup_reference to confirm the second-half row covers 2026-04. But since the answer is clarify due to conflict, the reference row isn't strictly needed. However, R7 ordering: item 3 (month without reference row) is checked before item 4 (conflict). If the month lacked a row, we'd return NO_APPLICABLE_REFERENCE. 2026-04 is within 2026 which is covered. The lookup_reference tool provides first-half and second-half rows; the second-half presumably covers months 07-12 and first-half 01-06. 2026-04 would be first-half. I could call lookup_reference("first-half") to confirm coverage exists. That's harmless and confirms item 3 passes. Let me do that to be safe — it doesn't change the outcome but confirms the month is covered so the correct clarification reason is CONFLICTING_GROSS_PAY rather than NO_APPLICABLE_REFERENCE.

Actually, the rules state "Only 2026 is covered" and 2026-04 is in 2026, so a row exists. But being careful, I'll call lookup_reference first-half to verify. It's an independent call I could have made earlier. Let me make it now.

The first-half reference row covers 2026-01 through 2026-06, so 2026-04 has a reference row. Item 3 of R7 passes.

Now the conflict: payroll gross_pay = 4188.34, contract gross_pay = 4163.34. They differ. Amendment: approved=true, effective_month=2026-02 (≤ 2026-04), but amount = 4218.34 ≠ payroll gross_pay 4188.34. Per R9, the amendment resolves the conflict only if its amount equals the payroll record's gross pay. It doesn't. So the conflict is unresolved → clarify with CONFLICTING_GROSS_PAY, citing R7 and R9.

No calculated monetary fields. Answer JSON:

{
  "decision": "clarify",
  "reason_code": "CONFLICTING_GROSS_PAY",
  "clauses": ["R7", "R9"],
  "explanation": "..."
}

The explanation should name the unresolved blocker and ask for its resolution. The payroll record's gross_pay (4188.34) conflicts with the contract gross_pay (4163.34), and the approved amendment (4218.34, effective 2026-02) does not resolve it because its amount differs from the payroll record's gross pay. Need an approved amendment whose amount equals 4188.34 (or a corrected record/contract) to resolve.