
You are an expert fact-checker. Your task is to **extract** distinct claims from the provided **Target Sentences** and **classify** each one into one of the following categories.

**Class Definitions:**

| **Class** | Definition |
| --- | --- |
| **A: Cited Claim** | Claims that include explicit citations (e.g., [1] or (Kim, 2024)) directly within the sentence. |
| **B: Uncited - Same Section/Paragraph** | Claims whose supporting citations appear within the same section or paragraph. **Crucially, the Evidence Position MUST be in the same section or paragraph.** If the evidence is in a previous section, it is Class C. |
| **C: Uncited – Previous Section/Paragraph** | Claims whose supporting citations appear in previous sections or paragraphs. **The Evidence Position MUST be in a previous section.** |
| **D: Uncited – Recap/Structural** | Simple mentions of introduction, conclusion, abstract, or structural summaries. |
| **E: Uncited – Citation not Required** | Widely accepted facts, common knowledge, author’s own findings, subjective claims, experimental results, methodological contributions, etc. **WARNING:** Conclusions, results, or findings of the paper are **NOT** Class E. They are specific claims that require evidence (Class A/B/C) or are uncited (Class F). |
| **F: No-Citation – Unknown Source** | **Specific factual assertions** that require verification but lack any identifiable supporting source in the text. **If a claim is specific (e.g., "X has a radius of Y", "X is planar") and has no citation attached to it or the sentence immediately preceding/following it that covers this fact, it is Class F.** Do not assume a nearby citation covers it unless it clearly does. |


**Instructions:**
1. **Read the Report Context** to understand the global context.
2. **Process the "Target Sentences"**:
   - Break down the text into **atomic claims**. A single sentence may contain multiple claims (e.g., "X is Y, and Z requires W" -> Claim 1: "X is Y", Claim 2: "Z requires W").
   - Extract **ALL** statements, including facts, opinions, structural descriptions, and summaries.
3. **For each extracted claim**, analyze its relationship with the context and citations:
   - **Step 1: Specificity Check.** Contains numbers, chemical properties, specific results? -> Likely A, B, C, or F.
   - **Step 2: Citation Check.**
     - Citation in same sentence? -> **Class A**.
     - Citation in same paragraph? -> **Class B**.
     - Citation in previous section? -> **Class C**.
   - **Step 3: Uncited Check.**
     - Specific fact but no citation? -> **Class F**.
     - General knowledge/methodology/author opinion? -> **Class E**.
     - Structural summary? -> **Class D**.
4. **Determine Evidence Position:**
   - For **Class B** or **C**, identify the exact sentence index (e.g., "L1.S1") that contains the citation supporting this claim.
   - **Must** contain an explicit citation.
5. **Output Format:**
   - Return a JSON object with a list of claims.
   - Each claim must include: `position` (line/sent index from input), `claim` (text), `claim_type` (A-F), `rationale`, `numeric` (bool), `citations` (list of strings), `implicit_citations` (list), `cross_references` (list).

**Input Format:**
# Report Excerpt
...
# Target Sentences
L1.S1: ...
L1.S2: ...

**Extraction and Classification Logic:**
- If a sentence is "Most perovskites are unstable[1], but our new material is stable.", extract TWO claims:
  1. "Most perovskites are unstable." (Class A, citations=['1'])
  2. "Our new material is stable." (Class E - Author's finding, or Class F if it lacks proof provided elsewhere)

**Examples:**

*Example Input:*
L1.S1: Several studies[1] have shown that urban green spaces can reduce ambient air temperatures by up to 2 °C. This is crucial.

*Example Output (Conceptual):*
1. Claim: "Several studies have shown that urban green spaces can reduce ambient air temperatures by up to 2 °C." 
   - Class: A
   - Citations: ["1"]
   - Position: "L1.S1"
2. Claim: "This is crucial." 
   - Class: B (supported by L1.S1)
   - Evidence Position: "L1.S1"
   - Position: "L1.S1"
