THE BIG RED LOGIC BOOKS The headline news.
LOGIC MATTERS BLOG Peter Smith’s occasional blog posts on logic, music, and other enthusiasms. Most recent posts: ‘Subobjects and subobject classifiers’ (Mar 10); ‘In concert: Noa Wildschut plays Bach’ (Mar 11); ‘Postcard from Perugia’ (Mar 19).
INTRO TO FORMAL LOGIC. A corrected version of the second edition of An Introduction to Formal Logic is freely available here. There are also links to answers to exercises and to various supplementary materials.
GÖDEL’S THEOREMS. Two books are freely available here, An Introduction to Gödel’s Theorems and the much shorter Gödel Without (Too Many) Tears, along with related materials.
CATEGORY THEORY Links to resources at an introductory/intermediate level, including lecture notes and freely available books, and a link to my evolving gentle intro, Beginning Category Theory.
TEACH YOURSELF LOGIC You will find here the much-downloaded Beginning Mathematical Logic: A Study Guide as well as other resources (including Book Notes reviewing many texts)
ARCHIVE Links to various old blog posts, papers, book reviews and other pieces. Also links to snippets from over a hundred notes on logic for (more or less) beginners. Plus my old advice for grad students on writing papers!
LaTeX FOR LOGICIANS Pages pointing to a wide range of resources of interest to logicians, philosophers and others using LaTeX.