From 8dc64784bc1d619ad1a65da31b19fb13fd2faee1 Mon Sep 17 00:00:00 2001
From: Hedongliang Liu <uniquelhdl@gmail.com>
Date: Wed, 20 Aug 2025 18:21:10 +0200
Subject: [PATCH] cleared repeated packages

---
 CELbeamer.cls         |  9 ++++---
 README.md             |  4 +++
 packages/packages.tex | 61 +++++++++++++++----------------------------
 3 files changed, 30 insertions(+), 44 deletions(-)

diff --git a/CELbeamer.cls b/CELbeamer.cls
index dfb3e6b..874567d 100644
--- a/CELbeamer.cls
+++ b/CELbeamer.cls
@@ -92,10 +92,11 @@
 \LoadClass[17pt,utf8,onlytextwidth]{beamer}
 % \renewcommand{\normalsize}{20pt}
 \renewcommand{\normalsize}{\fontsize{18pt}{24pt}\selectfont}
-% Babel-Paket wird nur bei deutscher Sprache benötigt
-\ifgerman
-  \RequirePackage[ngerman]{babel}
-\fi
+% If German language is used, the babel package is required.
+% For English, it is not required, but it ensures consistent hyphenation and date formats.
+% \ifgerman
+\RequirePackage[english, ngerman]{babel}
+% \fi
 \RequirePackage{csquotes}
 \RequirePackage{hyperref}
 \RequirePackage[absolute,overlay]{textpos}
diff --git a/README.md b/README.md
index 84c22bb..5e2d7d7 100644
--- a/README.md
+++ b/README.md
@@ -121,6 +121,10 @@ https://sdq.kastel.kit.edu/wiki/BibTeX-Literaturlisten
 ---------------
 Document class for CEL presentations in KIT design.
 
+`packages.tex`
+--------------
+TeX file to put all the necessary packages. Current version inherient from the old (before 2025) CEL beamer template.
+
 `logos/`
 --------
 This directory contains the KIT, CEL, and funding logos in various color variants as PDF.
diff --git a/packages/packages.tex b/packages/packages.tex
index e989369..702306a 100644
--- a/packages/packages.tex
+++ b/packages/packages.tex
@@ -1,49 +1,34 @@
 %%%%%%%%%%%%%%%%%%%%%%%
 % Usepackages
-%
-%\usepackage[ngerman]{babel}
-%\usepackage[latin1]{inputenc}
-\usepackage[T1]{fontenc}
-\usepackage{amssymb,amsthm}
-\usepackage{array}
-\usepackage{multicol}
-\usepackage{lipsum}
-\usepackage[overlay,absolute]{textpos}
-
-
-\usepackage{tabularx}
-
-
-
 % importing packages for encoding and fonts
+\usepackage[T1]{fontenc}
 \usepackage[utf8]{inputenc}
 
 \usefonttheme[onlymath]{serif}
 
-\usepackage[english,ngerman]{babel}
-
-% math stuff
-\usepackage{amssymb,amsthm}
+% Math stuff
+\usepackage{amsmath,amssymb,amsthm}
 \usepackage{bbm}
+\usepackage{dsfont} % more blackboard bold symbols like digits and lowercase letters
+\usepackage{bm} % bold math symbols
 
 \usepackage{array}
 \usepackage{multicol}
 \usepackage{lipsum}
+\usepackage{tabularx}
 
-\usepackage[overlay,absolute]{textpos}
-%\usepackage[absolute]{textpos}
-
-\usepackage{amsmath,amssymb}
-
-\usepackage{xkeyval}
+\usepackage{xkeyval} % for defining keys in commands and environments
 \usepackage{todonotes}
-\presetkeys{todonotes}{inline}{}
-\presetkeys{todonotes}{size=\tiny}{}
+\presetkeys{todonotes}{inline}{} % make todos inline by default
+\presetkeys{todonotes}{size=\tiny}{} % make todos font smaller by default
+\presetkeys{todonotes}{color=kit-yellow50}{} % make todos box color yellow by default
+\presetkeys{todonotes}{textcolor=kit-red}{} % make todos textcolor red by default
 
 % Links in pdf
 \usepackage[depth=4,open,openlevel=2]{bookmark}
 
 % Um bei Listen erklärenden Text in einem gleichmäßigen Abstand zu setzen: 
+% In order to set explanatory text in a uniform distance in lists:
 \usepackage{makebox}
 
 % SI units:
@@ -54,16 +39,14 @@
 % Tables
 \usepackage{booktabs}
 
-% For cancelling (errata)
-\usepackage{comment}
-\usepackage{soul}
+\usepackage{comment} % enable the envioment \begin{comment}
 
-\usepackage{cancel}
+% For emphasizing or cancelling 
+\usepackage{soul} % for text highlighting, \hl{highlight}, \ul{underline}, \st{strikeout}
+\usepackage[normalem]{ulem}
+\usepackage{cancel} % draw diagonal lines through math expressions, e.g. \cancel{a+b}, \bcancel{a+b}, \xcancel{a+b} for different styles
 
-% bold math for vector notation
-\usepackage{bm}
-\usepackage{xifthen}
-%\usepackage{adjustbox}
+%\usepackage{adjustbox} % allows to scale, resize, trim, clip, rotate, and frame content
 
 % TikZ and stuff
 \usepackage{tikz, pgfplots}
@@ -78,17 +61,15 @@
 %\tikzexternalize[prefix=TikzPictures/]
 
 
-\usepackage{dsfont}
 
 % Index finger
-\usepackage{bbding}
+\usepackage{bbding} % provvides decorative symbols like \Checkmark, \Cross, \ThumbsUp, \ThumbsDown, \Index, \PointingHand
 
 % ifthenelse
-\usepackage{ifthen}
+\usepackage{ifthen} % basic logics
+\usepackage{xifthen} % extended logics, e.g. \ifempty{arg}{true}{false}
 
 
-\usepackage[normalem]{ulem}
-
 % \mleft( and \mright) to avoid weird spaces before functions
 \usepackage{mleftright}