prolog-backtracking

Visualize Prolog backtracking and depth-first search execution through choice points.

1|Updated Mar 15, 2026

Search Tags:#backtracking #dfs #prolog #execution-model #logic-programming #choice-points

Ready to run

npx skills add https://github.com/hafley66/claude-research --skill prolog-backtracking

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: prolog-backtracking
Source: https://github.com/hafley66/claude-research/tree/main/skills/prolog-backtracking
Command: npx skills add https://github.com/hafley66/claude-research --skill prolog-backtracking

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This skill clarifies Prolog's execution model by explaining depth-first search (DFS) with chronological backtracking, showing how queries traverse facts and rules, handle failures, and enumerate solutions through choice points.

Core Features & Use Cases

Explains how goal evaluation creates choice points and how backtracking rewinds to the most recent untried alternative.
Demonstrates practical examples of single- and multi-solution predicates, and how determinism affects search paths.
Bridges concepts to related programming paradigms (RxJS, Go) to aid cross-language understanding.

Quick Start

Explain a basic Prolog program's DFS backtracking with a concrete example.

Frequently Asked Questions about prolog-backtracking

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How does Prolog backtracking work during depth-first search?▼

Prolog backtracking uses depth-first search to traverse facts and rules, creating choice points at alternative branches. When a goal fails, execution rewinds to the most recent untried choice point to continue searching the proof space.

How do choice points enumerate multiple solutions in Prolog?▼

Choice points store untried alternative clauses during goal evaluation. When Prolog backtracks, it navigates to these stored points, unbinds variables on the trail, and evaluates the next alternative to enumerate subsequent solutions.

What are common pitfalls with left recursion in logic programming?▼

Left recursion in logic programming causes infinite loops because the recursive call appears before the base case in the rule body. This prevents Prolog from establishing a terminating choice point, leading to non-exhaustive depth-first search.

How does variable unbinding on the trail affect Prolog determinism?▼

Variable unbinding on the trail resets bindings when backtracking occurs. Determinism categories dictate whether a predicate yields single or multiple solutions, directly affecting how the trail unwinds and whether choice points remain active.

Can I apply Prolog backtracking concepts to other programming paradigms?▼

Prolog backtracking concepts bridge to related programming paradigms like RxJS and Go. The execution model of navigating choice points translates to understanding reactive streams and concurrency patterns in these languages.

Why does my Prolog query fail to find solutions using DFS?▼

Prolog queries fail when depth-first search exhausts all choice points without satisfying goals, or encounters infinite loops from left recursion. The execution model reports failure, triggering chronological backtracking to explore alternative branches.