I’ve now retired the mid 2020 version of the TYL guide, and marked the new year by officially launching a replacement, retitled as *Logic: A Study Guide.* (Although the Guide’s title has changed, its webpage address stays the same, so as not to break external links.)

The Guide now takes the form of two PDFs. The first contains the rewritten Chapters 1 to 7. That’s three preliminary chapters about the aims and structure of the Guide, and then four chapters on very-elementary (“naive”) set theory, FOL, elementary model theory, and arithmetic/Gödel’s theorems. These have already been posted here, and many thanks for the most useful comments so far.

The second PDF contains Chapters 8 onwards, renumbered but otherwise unrevised from the last version of TYL. As the weeks and months go by, the first PDF should grow as more newly revised chapters are added, and the second PDF will correspondingly shrink. Or at least, that’s the plan!