This is a preprint of the following work: I. Jauslin, An Introduction to Lieb's Simplified Approach, 2025, Springer. It is the version of the author's manuscript prior to acceptance for publication and has not undergone editorial and/or peer review on behalf of the Publisher (where applicable). The final authenticated version is available online at: http://dx.doi.org/10.1007/978-3-031-81393-1 This directory contains the source files to typeset the book, and generate the figures. This can be accomplished by running make The data pertaining to the Big, Medium and Simple equations in the figures were generated using 'simplesolv' which is available from http://ian.jauslin.org/software/simplesolv This document uses a custom class file, located in the 'libs' directory, which defines a number of commands. Most of these are drop-in replacements for those defined in the 'article' class. Some extra functionality is provided in custom style files, located in the 'libs' directory. * Dependencies: pdflatex TeXlive packages: amsfonts color etoolbox graphics hyperref latex marginnote pgf standalone xcolor gnuplot GNU make * Files: Jauslin_2023c.tex: main LaTeX file libs: custom LaTeX class file figs: source code for the figures