♟️ Chess Endgames Planner

Authors:
Angelo Gianfelice (1851260)
Stefano Previti (2151985)
Course: Planning and Reasoning 2025/26 — Sapienza University of Rome

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🧩 Overview

This project explores Automated Planning and Reasoning in simplified chess endgame scenarios.
It combines PDDL planning and Indigolog reasoning to model, plan, and simulate forced checkmate sequences.

The domain focuses on positions where one side (White) has a material advantage, and the objective is to find a forced mate within a fixed number of moves on a 4×4 simplified chessboard.

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🧠 Project Structure

Chess_Endgames_Planner/
│
├── PDDL/
│   ├── domain.pddl                 # PDDL domain description (pieces, moves, predicates, etc.)
│   ├── problem1.pddl     # Mate in 1 (Smothered Mate)
│   ├── problem2.pddl     # Mate in 3 (Anastasia’s Mate)
│   └── problem3.pddl     # Mate in 5 (Damiano’s Mate)
│
├── Indigolog/
│   ├── chess.pl                    # Indigolog implementation of the chess domain and controllers
│   └── main.pl                     # Main program: legality & projection tasks

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⚙️ PDDL Domain and Planner

• Planner: ENHSP
• Heuristics tested: blind, hadd, hmax
• Search algorithms: GBFS, A*

Three problem instances of increasing complexity were solved:

Problem	Mate Type	Plan Length	Best Heuristic	Found Mate
1	Smothered Mate	3	blind/hadd/hmax	✅
2	Anastasia’s Mate	9	hadd/hmax	✅
3	Damiano’s Mate	15	hadd/hmax	✅

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🤖 Indigolog Implementation

The Indigolog implementation reuses the same predicates and actions as the PDDL domain.
It focuses on Anastasia’s Mate and supports the following reasoning tasks:

1. Controller Execution: Finds a legal sequence of moves leading to checkmate.
2. Legality Task: Verifies if a given sequence of actions is executable from an initial situation.
3. Projection Task: Simulates whether a condition (e.g., a piece position) will hold after executing a sequence.

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🧪 How to Run

PDDL

1. Install ENHSP.
2. Run a problem instance:

   java -jar enhsp.jar -o PDDL/domain.pddl -f PDDL/problem1.pddl -sp gbfs -h hadd

Indigolog

1. Install IndiGolog (requires SWI-Prolog).
2. Run the main program:

   swipl Indigolog/main.pl

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🧾 References

• ENHSP Planner's website
• ENHSP Planner's Repo