Self-reproducing object
Before we call something a self-rep, we want to have the feeling that, to the maximum extent possible, it explicitly contains the directions for copying itself. ~ D. R. Hofstadter[1]
A self-reproducing object, or self-rep, is an object within a computational system which can reproduce a copy of itself in a suitable environment. The concept of self-reps was introduced in 1979 by Douglas Hofstadter as a generalization of Gödelian reasoning in computability theory and the wikipedia:central dogma of molecular biology.
Gödelian reproduction
- Main article: Quine
The wikipedia:diagonal lemma enables construction of programs that interpret their own code as data. Specifically, for any legal syntax fragment Q which is open on a single variable, there is a closed fragment Q("Q") which applies that fragment to its own quotation. Applying the diagonal lemma in this fashion is called quining. A quine, named after wikipedia:William Van Orman Quine by Hofstadter, is an application which prefixes the fragment with the quotation, as in this 1979 example by Hofstadter[1]:
"yields falsehood when quined" yields falsehood when quined
Symmetrically, an eniuq is an application which suffixes the quotation after the code for the original fragment, as in the above paragraph of the article.
Kimian reproduction
- Main article: Error quine
A Kimian self-rep or error quine is a non-computational object which can reproduce itself in an environment that erroneously treats the object as an ordinary computational object. When interpreted as if it were a program, the error produced by the computational environment is equivalent to the original object, effectively producing a copy without containing instructions for copying. Kimian self-reps are named after wikipedia:Scott Kim by Hofstadter.[1]
Bayesian reproduction
- Main article: Ganguine
A ganguine is a self-rep which probabalistically reproduces itself by inferring its own source code. While a ganguine might not produce itself on the first attempt, it will eventually tend to produce copies of itself as the number of attempts increases. Ganguines are named after wikipedia:Paul Gauguin.[2]
References
- ↑ 1.0 1.1 1.2 D. R. Hofstadter, 1979. Gödel, Escher, Bach: an eternal golden braid. p499-503.
- ↑ K. Chandra, A. Liu, J. Ragan-Kelley, J. B. Tenenbaum, 2025. Gauguin, Descartes, Bayes: a diurnal golem's brain. Onward! 2025. https://dl.acm.org/doi/10.1145/3759429.3762631