# How to change the numbering of \part, \chapter, \section, … to alphabetical, Roman numbers, etc

I'm fairly new to LaTeX and I want to know how to change the way sections are numbered by default. I use LyX, and there it is relatively simple to change the way an enumeration is numbered, i.e.

1 foo
a bar
i baz


But I want to know if there is a way to do this by default for sections and subsections.

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You change section numbering by redefining the commands used to generate each section number. For example, the default article class uses something like

\renewcommand\thesection{\arabic{section}}
\renewcommand\thesubsection{\thesection.\arabic{subsection}}


with similar commands like \thesubsubsection and so on -- of course, there's also \thechapter (in the book and report class) and \thepart. Commands to typeset numbers include:

• \arabic (1, 2, 3, ...)
• \alph (a, b, c, ...)
• \Alph (A, B, C, ...)
• \roman (i, ii, iii, ...)
• \Roman (I, II, III, ...)
• \fnsymbol (∗, †, ‡, §, ¶, ...)
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If you have any more expertise or examples to add to this answer, I think this would be a good question to serve as a "canonical" question with a widely applicable and extensive answer. I suppose widening the scope of the question a bit would be acceptable as well, even though it's pretty open already. I might come back to this question when I have some time and look into it. The 2.5k views are promising for sure. –  doncherry Sep 30 '12 at 0:53

EDIT: As @Johannes_B pointed out, def is an inappropriate command for general use. The other answer still works.

Another way to do this is to put the command

\def\thesection{\alph{section}}


in the preamble, where alph can be susbtituted for arabic, roman etc as detailed in the other answer.

See:

http://wiki.lyx.org/FAQ/Numbering#sec-numbering

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Hi and welcome, def is a low level command and should be used by experienced users exclusively. It is much better to do renewcommand if needed. There is a whole security mechanism behind the scene that def does not have. –  Johannes_B Apr 7 at 12:52
Thanks, will edit –  Tim Apr 7 at 12:53