Text Formatting ⇒ Numerotation with letters

[poilou2607]

Hello,
I would like to have my subsusbections numbers like this : 1.1.1.a. , 1.1.1.b. ...

I tried the following code, but without success :
\setcounter{secnumdepth}{3} % Numérotation until subsubsections
\renewcommand*{\thesubsubsection}{\thesubsection.\alpha{subsubsection}}

while the following code works for 1.1.1.i. and 1.1.1.1. :
\renewcommand*{\thesubsubsection}{\thesubsection.\roman{subsubsection}}

\renewcommand*{\thesubsubsection}{\thesubsection.\arabic{subsubsection}}

Thank you very much for your help

[cgnieder]

You're using the wrong command. It's \alph{counter}. \alpha is used to insert an actual alpha in math mode.

Regards

[poilou2607]

Thank you