# What style/font is this?

Does anyone know how to create numbering for Theorem/lemma/… like this one in the image below, also any idea about the font name?

• Welcome to TeX.SX! You may have a look on our starter guide. – texenthusiast May 21 '13 at 2:02
• – Werner May 21 '13 at 6:43
• Can you make your question clearer? Do you want to automate the creation of theorem environments with drop cap numbers? – hpesoj626 May 21 '13 at 15:05
• @hpesoj626 Yes,this is my target. – user31009 May 21 '13 at 15:21
• I added an answer using the ntheorem package to create theorems with drop cap numbers. – Henri Menke May 21 '13 at 18:20

Remarks

I reproduced Heiko's answer using ntheorem. There is a tricky thing about it: You can't wrap the \lettrine into the [] of the \item as one would normally do for theorems. I get the error

! Argument of \@lettrine has an extra }.


if I do this. I don't know why, maybe somebody knows (Please comment).

Implementation

\documentclass{article}
\usepackage[ngerman]{babel}
\usepackage[T1]{fontenc}
\usepackage[sc]{mathpazo}
\usepackage{tgpagella}
\usepackage{microtype}
\usepackage{amsmath}
\usepackage{lettrine}
\usepackage{xcolor}
\usepackage{ntheorem}
\definecolor{theoremgray}{gray}{.5}
\makeatletter
\newtheoremstyle{mytheorem}%
\makeatother
\theoremstyle{mytheorem}
\theorembodyfont{\normalfont}
\theoremseparator{:}
\newtheorem{theorem}{Theorem}[subsection]
\setlength{\textwidth}{.85\textwidth}% just for reproducing the example
\begin{document}
\section{Sectiontitle}
\subsection{Subsectiontitle}
\begin{theorem}[Bezeichnungen]
Ist $G$ eine (multiplikativ geschriebene) Gruppe, so f"uhrt man
f"ur beliebige $g \in G$ und $M, N \subseteq G$ die Bezeichnungen
\begin{alignat*}{4}
&Mg &&= \{mg &&\mid m &&\in M\},\\
&gN &&= \{gn &&\mid n &&\in N\},\\
&MN &&= \{mn &&\mid m &&\in M, n \in N\}
\end{alignat*}
\end{theorem}
\end{document}


Output

• thanks for this code. I noticed a conflict with the package amsthm. for example try to use \begin{proof} something \end{proof} after adding the amsthm package. I got an error!. do you have an idea how can I fix this? – user31009 May 21 '13 at 20:29
• Section 3.2.2 of the ntheorem user manual states, that it is incompatible with amsthm. Some of the features of amsthm are implemented in ntheorem and loading it with \usepackage[amsthm]{ntheorem} will emulate them (It will provides the environments plain, defintion, remark and proof). Conclusion: You can't use ntheorem and amsthm at once. (I would stick with ntheorem instead) – Henri Menke May 21 '13 at 20:40

Also I have enlarged the number a bit for a better aligment with the top of the text.

\documentclass{article}
\usepackage[ngerman]{babel}
\usepackage[T1]{fontenc}
\usepackage[sc]{mathpazo}
\usepackage{tgpagella}
\usepackage{microtype}
\usepackage{amsmath}
\usepackage{lettrine}
\usepackage{xcolor}
\definecolor{theoremgray}{gray}{.5}

\setlength{\textwidth}{.85\textwidth}% just for reproducing the example

\begin{document}
\lettrine[
loversize=.11,
findent=0.5em,
nindent=0pt,
]{\textcolor{theoremgray}{1.1.1}}{\textls{Bezeichnungen:}}
Ist $G$ eine (multiplikativ geschriebene) Gruppe, so f"uhrt man
f"ur beliebige $g \in G$ und $M, N \subseteq G$ die Bezeichnungen
\begin{alignat*}{4}
&Mg &&= \{mg &&\mid m &&\in M\},\\
&gN &&= \{gn &&\mid n &&\in N\},\\
&MN &&= \{mn &&\mid m &&\in M, n \in N\}
\end{alignat*}
\end{document}


Missing:

• Wrapping the visual markup into proper logical markup by defining a theorem style and setting up a theorem, for example.

The answer of Henri Menke shows this using package ntheorem as example.

• You should use \usepackage[sc]{mathpazo} for true small caps (and better kerning). – NauC May 21 '13 at 7:12
• How can I obtain letterspacing for the small caps similar to the example picture by OP? – Henri Menke May 21 '13 at 12:15
• @HenriMenke Thanks, missed that. Answer updated with using \textls of package microtype for letter spacing. – Heiko Oberdiek May 21 '13 at 12:19
• alignment of the equations is not simply align* from amsmath -- the original example shows the left-hand side aligned flush left. can probably be done with alignat* but i haven't tried. – barbara beeton May 21 '13 at 14:04
• @barbarabeeton Thanks, just for fun I have added additional alignments. – Heiko Oberdiek May 21 '13 at 14:57

Partial solution: the font is loaded with the package mathpazo.

• Can you post the TeX code that you are using? – Heiko Oberdiek May 21 '13 at 3:07
• @HeikoOberdiek, sorry, I deleted the file. But you just need to load the package with \usepackage{mathpazo}. – Sigur May 21 '13 at 3:11
• Could you then please reproduce the file and upload the code? – Svend Tveskæg May 22 '13 at 15:06
• @SvendTveskæg, do you want the code for the 3 equations? You can copy it from Heiko's answer below tex.stackexchange.com/a/115323/14757. – Sigur May 22 '13 at 17:06