What is Prolog?

Prolog is a programming language that lets you describe facts and rules about a problem, and then asks the computer to find answers that fit those rules. It’s especially good for tasks that involve logical reasoning and relationships.

Let's break it down

  • Programming language: a way to tell a computer what to do.
  • Describe facts: you write simple statements like “Socrates is a man.”
  • Rules: you set up logical connections, such as “All men are mortal.”
  • Ask the computer: you pose a question, like “Is Socrates mortal?” and Prolog works out the answer using the facts and rules you gave it.
  • Logical reasoning: the process of drawing conclusions from given information, similar to solving a puzzle.

Why does it matter?

Prolog shows a different way to think about programming-by focusing on what is true rather than how to compute it. This helps people solve problems that are hard to express with traditional step-by-step code, like puzzles, planning, or understanding complex relationships.

Where is it used?

  • Artificial intelligence research: building expert systems that mimic human decision-making.
  • Natural language processing: parsing sentences and understanding grammar rules.
  • Knowledge databases: storing and querying large sets of interrelated facts, such as medical diagnosis systems.
  • Education: teaching logic and problem-solving concepts in computer science courses.

Good things about it

  • Very expressive for representing relationships and rules.
  • Automatic backtracking finds solutions without extra code.
  • Concise code: many problems need only a few lines.
  • Strong theoretical foundation in formal logic, making reasoning about programs easier.
  • Good for rapid prototyping of AI and rule-based systems.

Not-so-good things

  • Can be slower than imperative languages for large, data-intensive tasks.
  • Limited built-in libraries and tooling compared to mainstream languages like Python or Java.
  • Steeper learning curve for programmers used to step-by-step coding.
  • Not ideal for low-level system programming or performance-critical applications.