In the Definition and Lemma body environment I want non italic content

Question

I am using a book style file and in the preamble I defined some theorem environment. But in the Definition and Lemma part I want nonitalic content. Please suggest. My preamble are

\newtheorem{theorem}{Theorem}[chapter]
\newtheorem{exercise}{Exercise}[chapter]
\newtheorem{example}{Example}[chapter]
\newtheorem{definition}{Definition}[chapter]
\newtheorem{lemma}{Lemma}[chapter]

After so many years being a user of TeX.SE you have neither learned of a MWE nor how to format posts :-( And you mean book class file, most likely) — , Jun 15 '17 at 07:09
Mr. Christian Hupfer ! Sorry I am not an expert of TeX like you, so I am asking for help. — Deepesh Patel, Jun 15 '17 at 09:43

score 0 · Answer 1 · answered Jun 15 '17 at 07:15

0

Below suggestion is not good but it works...

\newtheorem{odefinition}{Definition}[chapter]
\newenvironment{definition}{\begin{odefinition}\rm}\end{odefinition}}

\newtheorem{olemma}{Lemma}[chapter]
\newenvironment{lemma}{\begin{olemma}\rm}\end{olemma}}

answered Jun 15 '17 at 07:15

MadyYuvi

13,693

Yes, it works - no it is not good style. Much better is to use the amsthm package. – Andrew Swann Jun 15 '17 at 07:40
1

\rm has been obsolete and deprecated for more than 20 years. – egreg Jun 15 '17 at 08:04
Dear Andrew Swann ! As you suggested above, both are not working. When I am using amsthm then it is giving error already defined. – Deepesh Patel Jun 15 '17 at 09:40

score 0 · Answer 2 · answered Jun 15 '17 at 07:42

0

You can use the ntheorem package:

\documentclass{book}
\usepackage{ntheorem}
\newtheorem{tm}{Theorem}[chapter]
\theorembodyfont{\upshape}
\newtheorem{lm}{Lemma}[chapter]
\newtheorem{defi}{Definition}
\begin{document}
  \begin{tm}It happens that $2+2=4$\end{tm}
  \begin{lm}Why not?\end{lm}
\end{document}

answered Jun 15 '17 at 07:42

José Carlos Santos

4,803

Dear Sir ! This ntheorem is also not working. Actually, I am using a class file of a book given by the publisher. – Deepesh Patel Jun 16 '17 at 05:19
@DeepeshPatel Can you please explain in which way it is not working? – José Carlos Santos Jun 16 '17 at 06:16

In the Definition and Lemma body environment I want non italic content

2 Answers2