# User-specific numbering of statements

How to get the user specific numbering like it is shown below?

*NSET,NSET=FixedBoundary                                                               (i4)
1,4,8                                                                                (i4.1)
Statement (i4) assigns nodes to a node set. FixedBoundary is the name of the node set
to which nodes 1,4,8 in statement (i4.1) will be assigned. In the present analysis,
nodes 1,4,8 correspond to the nodes at the fixed boundary of bimorph beam.
*NSET,NSET=POTENTIAL                                                                   (i5)
9
Statement (i5) assigns node 9 to the node set POTENTIAL.

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Welcome to TeX.SE. It is always best to compose a fully compilable MWE including the \documentclass and the appropriate packages that shows what you have tried so far. In this case it would go a long way towards clarifying the question as I am not understanding what output you are tying obtain. –  Peter Grill Sep 5 '12 at 3:32

OK. I am giving this question a try by answering what I think you're looking for:

## Code

\documentclass{article}
\usepackage{amsmath}
\begin{document}

\begin{align*}
\rm ^*NSET, NSET= FixedBoundary \tag{i4} \label{eqn: i4} \\
1,4,8 \tag{i4.1} \label{eqn: i4.1}
\end{align*}

Statement \eqref{eqn: i4} assigns nodes to a node set. FixedBoundary is the name of the
node set to which nodes 1,4,8 in statement \eqref{eqn: i4.1} will be assigned. In the
present analysis, nodes 1,4,8 correspond to the nodes at the fixed boundary of bimorph  beam.

\end{document}

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Very interesting, I didn't know yet about \tag. –  Tom Bombadil Sep 21 '12 at 22:15