Executable Archaeology: Reanimating the Logic Theorist from its IPL-V Source

Fuente: arXiv
Saved in:
Bibliographic Details
Main Author: Shrager, Jeff
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911514675380224
author Shrager, Jeff
author_facet Shrager, Jeff
contents The Logic Theorist (LT), created by Allen Newell, J. C. Shaw, and Herbert Simon in 1955-1956, is widely regarded as the first artificial intelligence program. While the original conceptual model was described in 1956, it underwent several iterations as the underlying Information Processing Language (IPL) evolved. Here I describe the construction of a new IPL-V interpreter, written in Common Lisp, and the faithful reanimation of the Logic Theorist from code transcribed directly from Stefferud's 1963 RAND technical report. Stefferud's version represents a pedagogical re-coding of the original heuristic logic into the standardized IPL-V. The reanimated LT successfully proves 16 of 23 attempted theorems from Chapter 2 of Principia Mathematica, results that are historically consistent with the original system's behavior within its search limits. To the author's knowledge, this is the first successful execution of the original Logic Theorist code in over half a century.
format Preprint
id arxiv_https___arxiv_org_abs_2603_13514
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Executable Archaeology: Reanimating the Logic Theorist from its IPL-V Source
Shrager, Jeff
Artificial Intelligence
Logic in Computer Science
Programming Languages
Symbolic Computation
The Logic Theorist (LT), created by Allen Newell, J. C. Shaw, and Herbert Simon in 1955-1956, is widely regarded as the first artificial intelligence program. While the original conceptual model was described in 1956, it underwent several iterations as the underlying Information Processing Language (IPL) evolved. Here I describe the construction of a new IPL-V interpreter, written in Common Lisp, and the faithful reanimation of the Logic Theorist from code transcribed directly from Stefferud's 1963 RAND technical report. Stefferud's version represents a pedagogical re-coding of the original heuristic logic into the standardized IPL-V. The reanimated LT successfully proves 16 of 23 attempted theorems from Chapter 2 of Principia Mathematica, results that are historically consistent with the original system's behavior within its search limits. To the author's knowledge, this is the first successful execution of the original Logic Theorist code in over half a century.
title Executable Archaeology: Reanimating the Logic Theorist from its IPL-V Source
topic Artificial Intelligence
Logic in Computer Science
Programming Languages
Symbolic Computation
url https://arxiv.org/abs/2603.13514