First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic of logic and Aristotle. It is a clear statement about the discovery of logic. It does not need another sentence for context. This follows the rule of Topic Sentence. Why other lines are not chosen? The other paragraphs are not chosen because they do not stand alone. For example, Paragraph 2 starts with 'There', which is a pronoun and needs context. Paragraph 3 starts with 'Since', which is a conjunction. Paragraph 4 starts with 'These', which refers to something mentioned before.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the discussion about logic. It gives a final point about how logic is used today. This follows the Conclusive Words rule.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects with Paragraph 1 because it continues the idea about Aristotle. The phrase 'There he documented' shows that it talks about what Aristotle did. This follows the Logical Order rule.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects with Paragraph 2 because it talks about changes in logic after Aristotle. The word 'Since' shows a time change. This follows the Chronological Order rule.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects with Paragraph 3 because it explains what has been done with the new types of logic. The phrase 'These types of logic' refers back to the systems mentioned in Paragraph 3. This follows the Noun Pronoun Rule.