Accessible Open Logic Text — Complete English HTML and EPUB edition
The Open Logic Text is a free textbook covering mathematical logic, from sets and formal proofs to computability and the limits of formal reasoning. This English edition makes the book available as accessible web pages and a downloadable ebook. Read the book online Choose Read for the text and equations, Listen / words only for a reading version that expresses mathematical symbols in words, or Explore equations to examine the mathematics in more detail. Source links let you check passages against the original. The pages support keyboard navigation, adjustable reading preferences and mathematical markup designed for assistive software. For offline reading, download the EPUB and open it in an ebook reader. Alternatively, download and extract the HTML ZIP, then open index.html. The ZIP is the offline copy; the online link above opens the book directly. The Listen option can use your browser or computer's installed voice when you press Play. A prerecorded audiobook is not included. The edition has passed automated accessibility and reading tests; a complete evaluation with screen-reader and braille-display users is still needed. This edition follows the main Open Logic book. The international catalogue also offers a separate English preservation edition containing additional optional and alternative source material. Original text: The Open Logic Project and its credited contributors. Shared under Creative Commons Attribution 4.0. This is an independent accessibility adaptation and does not imply endorsement by the Open Logic Project. The adaptation was produced with OpenAI Codex gpt-5.6-sol, Ultra. Original author and contributor credits are preserved. This complete edition follows earlier partial releases. The earliest partial release remains listed for historical reference, with its files restricted after a documented privacy issue. The files in this edition are publicly available. Checksums and detailed validation results are included among the downloads.