# Explanation of the formulas in LaTeX

Package available on ctan.org.

Package available in Ubuntu in package texlive-science starting from version 19.4 Disco Dingo.

Package `eqexpl`

was developed as an answer to question on
StackExchange for
giving the ability to make «perfect» explanation of components of a
formula, not just the enumeration.

Requirements:

- The variables (left side) must be aligned right..
- The dash must be aligned center one under another.
- The explanation (right side) must be justified, the last string
must be aligned left and
- if the explanation takes more than one line, the left side of explanation must be aligned (second explanation in the example).

The package adds new environment `eqexpl`

with a command `\item`

with
one required parameter — variable to explain. The explanation in
the example above was made with the code in preamble

```
\usepackage{eqexpl}
\eqexplSetDelim{=}
```

and in document

```
\begin{eqexpl}[25mm]
\item{$H_s$}significant wave height, equal to the average of the
highest 1/3 of the waves
\item{$\Delta$}relative buoyant density, equal to $\rho_r / \rho_w -
1$, where $\rho_w$ is the water density
\item{$D_{n50}$}nominal diameter defined in Equation (2)
\end{eqexpl}
```

Width of the field for explained variables could be set with optional argument, default is 10 mm

```
\begin{eqexpl}[15mm]
```

Delimiter could be set with command `\eqexplSetDelim{delimiter}`

Parenthesis («where») could be set with the command
`\eqexplSetIntro{where}`

, the parenthesis printed only for the first
item in the explanation.

For formula variables in the explanation use usual string envirinment (dollar sign)

```
\item{$R_s$}total section resistance, Ohm.
```