Schaefer’s Theorem

Schaefer's Theorem is a key result in computer science and mathematical logic. It establishes that certain types of decision problems (specifically, problems involving Boolean functions) can be categorized based on their complexity. The theorem states that if a problem can be defined using a specific set of simple operations or functions, it can be classified as either being "easy" to solve (solvable in polynomial time) or "hard" (NP-complete), depending on the structure of those functions. This helps us understand the limits of what can be efficiently computed and guides researchers in studying computational complexity.