# align text in math mode

I have the following equation (I use MathType and then exctract it in LaTeX):

$$\begin{array}{*{20}{c}} {\begin{array}{*{20}{l}} {{\textrm{Dot product:}}}&{{\rm{ }}{\sigma _{ij}}{n_j} \Leftrightarrow {\bf{\sigma n}}} \end{array}}\\ {\begin{array}{*{20}{c}} {{\textrm{Double dot product:}}}&{\left\{ \begin{array}{l} {L_{ijkl}}{\varepsilon _{kl}} = {\bf{L\varepsilon }}\\ {L_{ijkl}}{T_{klpq}} = {\bf{LT}} \end{array} \right.} \end{array}} \end{array}$$


which produces

How is it possible to align the text in the left?

Thanks

MathType is not really doing a good work: it's much simpler to type in LaTeX directly.

\documentclass{article}
\usepackage{amsmath}

\begin{document}

\begin{alignedat}{2} &\text{Dot product:} &\quad& \sigma_{ij}{n_j} = \sigma\mathbf{n} \\ &\text{Double dot product:} &\quad& \begin{cases} L_{ijkl}\varepsilon_{kl} = \mathbf{L}\varepsilon \\ L_{ijkl}T_{klpq} = \mathbf{L}\mathbf{T} \end{cases} \end{alignedat}

\end{document}


This answer is similar to the one by Enrico, but is using aligned instead of alignedat.

\documentclass{article}
\usepackage{mathtools}
\begin{document}
\begin{aligned} & \textrm{Dot product:} && \sigma_{ij} n_j \Leftrightarrow \mathbf{\sigma n} \\ & \textrm{Double dot product:} && \begin{cases} L_{ijkl} \varepsilon_{kl} = \mathbf{L\varepsilon} \\ L_{ijkl} T_{klpq} = \mathbf{LT} \end{cases} \end{aligned}
\end{document}


• I guess I will receive many answers. Indeed MathType does not do do a good job at all! Thank you very much. – Dimitris Nov 17 '15 at 10:55

Here is a much simpler code with alignedat and cases environments. Use the bm package to have bold Greek letters.You don't need all those pairs of { }. Also note font commands such as \rm,\bf, &c. shouldn't be used as they're plain TeX commands, and they don't work well w.r.t. New Font Selection Scheme (N.F.S.S.) which has been new for more than 20 years…

\documentclass{amsart}
\usepackage{amsmath, bm}

\begin{document}

\begin{alignedat}{2} & \textrm{Dot product:}&&\quad\sigma _{ij}n_j\Leftrightarrow \bm{\sigma}\mathbf{n}\\ & \textrm{Double dot product:} &\enspaAce & \begin{cases} L_{ijkl}\varepsilon _{kl} = \mathbf{L}\bm{\varepsilon }\\ L_{ijkl}T_{klpq} = \mathbf{LT} \end{cases} \end{alignedat}

\end{document}


• Why do you include amssymb and amsfonts? As far as I can see you do not use their functionality in the example. – Henri Menke Nov 17 '15 at 15:26
• @Henry Lenke: You're right. I simply use the preamble of an answer to a previous question. Actually, in a first version of my answer, I used boldsymbol instead of \bm` to bolden Greek letters. Thanks for pointing the confusing preamble. – Bernard Nov 17 '15 at 16:55