Ninth annual
ICFP Programming Contest
Hosted by Carnegie Mellon University's POP Group

An Urgent Appeal

Dear Colleague:

In 1967, during excavation for the construction of a new shopping center in Monroeville, Pennsylvania, workers uncovered a vault containing a cache of ancient scrolls. Most were severely damaged, but those that could be recovered confirmed the existence of a secret society long suspected to have been active in the region around the year 200 BC.

Based on a translation of these documents, we now know that the society, the Cult of the Bound Variable, was devoted to the careful study of computation, over two millennia before the invention of the digital computer.

While the Monroeville scrolls make reference to computing machines made of sandstone, most researchers believed this to be a poetic metaphor and that the "computers" were in fact the initiates themselves, carrying out the unimaginably tedious steps of their computations with reed pens on parchment. A few have conjectured a city-sized machine powered by falling sand, but no physical evidence of such a device has been discovered.

Among the documents found intact in the Monroeville collection was a lengthy codex, written in no known language and inscribed with superhuman precision. It is believed to be the masterwork of the Cult's scholarship, and as such it carries immense potential to advance our understanding of history—and possibly of computing as well. Unfortunately, the codex eluded interpretation, and over the decades, study of the Monroeville scrolls has slipped into obscurity. Since 1978, the codex has been stored in the basement of the Carnegie Museum of Natural History.

Two weeks ago, during a visit to the excavation site for a new computer science building at CMU, workers discovered a set of inscribed tablets that proved to be the Rosetta Stone for interpreting the Monroeville codex. The tablets precisely specify the Cult's computing device, known to initiates as the "Universal Machine." Although there is still no evidence that the cult succeeded in constructing their machine, it is a reasonably simple task to emulate it on modern hardware.

We can now say with certainty that the codex is in fact a program, intended for execution on the Universal Machine. Our initial exploration of the codex suggests that the Cult's ideas about programming were very sophisticated, if somewhat peculiar to the modern eye. One cannot help but wonder what the Cult might have achieved had they had access to modern electronics and type theory.

I have enlisted the help of the CMU Principles of Programming group in creating a venue for study of the codex. We invite you to participate in this investigation. The codex and a translation of the Universal Machine (UM) specification are available for download from our web site. We encourage you to implement the UM and begin your own exploration of the codex. When you are prompted to enter a decryption key, type the following string: (\\v.vv)06FHPVboundvarHRAk

The Cult's scholarly publications are of particular interest to us. Because the Cult's journals were circulated on sandstone tablets, editors imposed very strict length limitations. Consequently, authors aggressively compressed their articles. A typical publication would have the following form:


Publications are of varying value; some will represent a greater contribution than others. Given our understanding of the Cult's publication process, we believe there is a mechanism within the codex that will verify a set of publications and compute their total value.

On a personal note, being inspired by the scholarship of the Cult, I have decided to dedicate the remainder of my days to a solitary study of computation and programming languages. However, before embarking on my monastic transformation, I wish to see that the world is well on its way to uncovering the secrets of the Codex.

Therefore, I ask that you submit as many publications as you can by noon EDT on July 24, 2006, at which time I will be taking my orders. My colleagues in the CMU POP group assure me that at that time, the teams that have made the greatest contribution to the effort shall be identified for special recognition.

Good luck and thank you for your assistance.


Professor Emeritus Harry Q. Bovik
Computational Archaeolinguistics Institute
Carnegie Mellon University

Contest Materials

UM Specification

Specification for the Universal Machine. Text format.


codex.umz (VOLUME ID 9)
MD5 hash e328209bd65ade420371d7bd87b88e4f
SHA-1 hash 088ac79d311db02d9823def598e48f2f8723e98a
Decryption key (\\v.vv)06FHPVboundvarHRAk


Benchmark for the Universal Machine. Expected output.
MD5 hash1c604d454de05d04afdabd2c63fb27fb
SHA-1 hashc2ee087aa661e81407fbcf0d9d7e503aff9b268e

Reference Implementation (1024 bytes)
CMU Reference implementation of the Universal Machine.

This implementation supports all UM programs, including uncompressed .um files and self-decompressing .umz files. To use this implementation to run a UM binary called, simply concatenate the two files together:

cat >

The resulting binary can be run in any compliant universal machine implementation, including itself.