Prolog Study Notes

Arithmetic in Prolog

Learn how Prolog evaluates arithmetic expressions with is/2, the difference between unification and arithmetic comparison, and common numeric predicates.

assert and retract

How Prolog programs modify their own clause database at runtime using assert, asserta, assertz, retract, and retractall.

Backtracking Explained

How Prolog recovers from failed goals and finds multiple solutions by returning to choice points, and what that means for how programs actually execute.

Building a Family Tree Solver in Prolog

A hands-on walkthrough of modeling a family tree as Prolog facts and rules, then querying it for relationships like siblings, grandparents, and ancestors.

Constraint Logic Programming

How CLP(FD) extends Prolog with propagating constraints over finite domains, replacing brute-force generate-and-test with early pruning.

DCGs (Definite Clause Grammars)

How Prolog's --> notation compiles grammar rules into difference-list predicates, enabling parsing, generation, and embedded computation in one syntax.

Debugging Prolog Programs

Master Prolog's built-in tracer, spy points, and common failure patterns to systematically debug logic programs.

Facts and Rules in Prolog

How Prolog knowledge bases are built from facts and rules, including how conjunctions (AND) and multiple clauses (OR) combine to express logic.

findall, bagof, and setof

The three built-in all-solutions predicates that collect every proof of a goal into a list, each with different rules for failure, grouping, and duplicates.

Higher-Order Predicates in Prolog

How Prolog treats goals as ordinary data, enabling call/N, maplist, foldl, include, exclude, and partition to parameterize control flow.

Installing SWI-Prolog

A practical walkthrough of installing SWI-Prolog on Windows, macOS, and Linux, and verifying the installation from the interactive top-level.

List Processing Built-ins

Master Prolog's standard list library predicates, member/2, append/3, length/2, reverse/2, nth0/3, maplist/2-4, and findall/3, for common list tasks without ha…

Lists in Prolog

Learn how Prolog represents lists as recursive [Head|Tail] structures and how unification lets you construct, deconstruct, and pattern-match them.

Modules in Prolog

Learn how Prolog's module system namespaces predicates, controls visibility, and enables code reuse across larger logic programs.

Negation as Failure

How Prolog's negation-as-failure (\+) works, why it reflects a closed-world assumption rather than classical logical negation, and the pitfalls of negating unb…

Prolog and AI Search Algorithms

See how classic AI search strategies, depth-first, breadth-first, and best-first, map onto Prolog's own backtracking engine and how to implement them explicitl…

Prolog and Natural Language Processing

Explore how Prolog's Definite Clause Grammars and unification make it a powerful tool for parsing and generating natural language.

Prolog Best Practices

Practical guidelines for writing correct, efficient, and maintainable Prolog code — from clause ordering to cut discipline and pitfalls to avoid.

Prolog for Expert Systems

Learn how Prolog's rule-based inference engine maps naturally onto expert system architecture, from knowledge bases to forward and backward chaining.

Prolog Interview Questions

The concepts, coding prompts, and common mistakes that come up when Prolog and logic programming are assessed in technical interviews or coursework.

Prolog Quick Reference

A condensed reference for Prolog syntax, essential built-in predicates, operators, and list notation for quick lookup while coding.

Prolog Syntax and Terms

A tour of Prolog's core data representation: atoms, numbers, variables, compound terms, and the [Head|Tail] list notation.

Prolog vs Imperative Languages

A comparison of Prolog's declarative, logic-based approach with the imperative, step-by-step style of languages like Python, Java, and C.

Queries and the Prolog Interpreter

An introduction to how Prolog queries work: typing goals at the ?- prompt, reading bound variables and backtracking with ;, and understanding how the interpret…