Unification

A simple Clojure implementation of the unification algorithm described in chapter 4 of the book Structure and Interpretation of Computer Programs (Abelson et al., 1996). I did this to fulfill an assignment for the CS4720 Artificial Intelligence course at SUU.

Usage

The query function allows you to search through a database of facts to find any entries that satisfy a given query by unifying the query with each fact. Installation:

Since this library is not available in Clojars or other package repositories, you'll need to clone the repository or include the relevant source files in your project manually.

Adding to your project:

1. Clone or download the source code from the repository.
2. Ensure the namespaces are properly included in your project files.
3. Import the required namespace:

(ns your-namespace
  (:require [unification.db :as db]))

Example Usage:

1. Basic Fact Matching:

(def facts
  '[(likes alice pizza)
    (likes bob ice-cream)
    (likes carol pizza)])

(db/query '(likes ?who pizza) facts)
;; => [{'?who 'alice} {'?who 'carol}]

2. Matching with Multiple Variables:

(def facts
  '[(likes alice pizza)
    (likes bob ice-cream)])

(db/query '(likes ?who ?what) facts)
;; => [{'?who 'alice, '?what 'pizza}
;;     {'?who 'bob, '?what 'ice-cream}]

3. Nested Query:

(def facts
  '[(and (likes alice pizza) (dislikes alice broccoli))
    (and (likes bob pizza) (dislikes bob carrots))])

(db/query '(and (likes ?who pizza) (dislikes ?who broccoli)) facts)
;; => [{'?who 'alice}]

TODO

1. Implement logic operators.

License

Copyright © 2024 Johnny M.

This program and the accompanying materials are made available under the terms of the Eclipse Public License 2.0 which is available at http://www.eclipse.org/legal/epl-2.0.

This Source Code may also be made available under the following Secondary Licenses when the conditions for such availability set forth in the Eclipse Public License, v. 2.0 are satisfied: GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version, with the GNU Classpath Exception which is available at https://www.gnu.org/software/classpath/license.html.