# Adding constant to function (vspace) argument?

How can I get Latex to add a constant to a value as part of a \vspace argument?

Here's my minimal example:

\documentclass{article}
\usepackage{calc}

\begin{document}
ab
%\vspace{20mm+10mm} %documentation of the calc package says it needs at least one dimen register
\newlength{\mylength}\setlength{\mylength}{20mm} \vspace{\mylength+10mm}
\\cd
\end{document}


Which always produces ab +10mm cd.

• \vspace{\dimexpr\mylength+10mm\relax}; but \vspace{\mylength}\vspace{10mm} is pretty much equivalent, because the second skip won't be used as a break point (unless \lastskip or \unskip are involved). – egreg Apr 7 '13 at 16:37

\vspace{\dimexpr\mylength+10mm\relax}

You won't need the calc package.