Semi-formal Logic

Semi-formal logic combines elements of both formal and informal logic. It uses structured rules but allows for uncertainty and natural language interpretation.

Key Features:

• Combines rules (formal) with context (informal)

• Can include degrees of belief or probability

• Suitable for systems needing both structure and flexibility

Example:

"If the temperature is below 0°C, and the road is wet, there’s a high chance of ice."

This sentence has structure, but includes uncertainty (“high chance”).

Used in: Legal AI, expert systems, decision support tools, ethical AI

Types of Semi-formal Logic:

• Fuzzy logic

• Probabilistic logic

• Rule-based systems with exceptions