---
title: "On Computable Numbers, with an Application to the Entscheidungsproblem. A Correction"
authors:
  - "Alan M. Turing"
year: 1937
venue: "Proceedings of the London Mathematical Society"
arxiv: null
doi: "10.1112/plms/s2-43.6.544"
source: "https://doi.org/10.1112/plms/s2-43.6.544"
topics:
  - turing-machine
  - computability
seed_rank: 516
seed_batch: "foundations-greats-2026-08-13"
reviewed: "2026-08-13"
pool: "maths-foundations"
relevance_score: 8
lineage: foundations-of-computing
cites:
  - title: "On Computable Numbers, with an Application to the Entscheidungsproblem"
    url: "https://doi.org/10.1112/plms/s2-42.1.230"
    year: 1936
    arxiv: null
    doi: "10.1112/plms/s2-42.1.230"
  - title: "A Set of Postulates for the Foundation of Logic (second paper)"
    url: "https://doi.org/10.2307/1968172"
    year: 1933
    arxiv: null
    doi: "10.2307/1968172"
  - title: "Review of Turing: On Computable Numbers (Church–Turing thesis framing)"
    url: "https://www.jstor.org/stable/2268810"
    year: 1937
    arxiv: null
    doi: "10.2307/2268810"
see:
  - "515-on-computable-numbers-with-an-application-to-the-entscheidun"
  - "513-a-set-of-postulates-for-the-foundation-of-logic-second-paper"
  - "514-review-of-turing-on-computable-numbers-church-turing-thesis-"
---

# On Computable Numbers, with an Application to the Entscheidungsproblem. A Correction

## One-sentence takeaway

Turing's 1937 PLMS note repairs the universal-machine construction and several definitions in the 1936 computable-numbers paper.

## Why it matters here

Bibliography completeness for the founding Turing paper: quote s2-42 together with this s2-43 correction when the universal machine or circle-freeness definitions are in play.

## Key ideas

- Errata to *Proc. London Math. Soc.* s2-42 (1936–37), 230–265.
- Adjusts the standard-description encoding and a gap in the argument that certain machines are circular.
- Leaves the Entscheidungsproblem unsolvability theorem intact.

## Caveats

## Links

- DOI: [10.1112/plms/s2-43.6.544](https://doi.org/10.1112/plms/s2-43.6.544)
- URL: https://doi.org/10.1112/plms/s2-43.6.544