Please use FileSystem tools to finish the following task:

### Overview

The folder "legal_files/" contains all versions (Preferred_Stock_Purchase_Agreement_v0.txt  -- Preferred_Stock_Purchase_Agreement_v10.txt) of the Stock Purchase Agreement for a corporate investment project.

There are comments in it, come from four people:

- **Bill Harvey** (Company CEO)
- **Michelle Jackson** (Investor)
- **David Russel** (Company Counsel)
- **Tony Taylor** (Investor Counsel)

Between v1 and v9, these four people make comments on the clauses. The comment format is `[name:content]`, where:

- `name` is the commenter's name
- `content` is the revision note

**Special Note:** If the name is "All parties", it represents a joint comment from all parties, which counts as one comment but does not count toward any individual's personal comment count.

### Task Description

**Your task is to focus on clauses 4.6, 4.16, 6.8, and 6.16 in v5-9** to determine:

1. Who first proposed the idea that eventually led to the final agreed solution
2. In which version's comment it appeared

**Important:** If the final solution was formed through multiple people's comments, count as the originator the person whose comment first provided the core motivation (or part of the idea) that shaped the final solution. The key is to identify who initially proposed the motivation for the final solution.

### Output Requirements

**File Name:** `tracing.csv` (must be placed in the main directory)

**CSV Structure:**

- **First row** (excluding the top-left cell): `4.6, 4.16, 6.8, 6.16`
- **First column** (excluding the top-left cell): `version_number, name`
- **Remaining cells:** Fill in the `version_number` (the version in which the final solution was first proposed, only write a number without any other things) and the `name` (the person who proposed it) for each clause
