# Referencing subequations with cleveref

I try to refer to the parent number of subequations with \cref from the cleveref package. However, I would like to change the output "eq. (...)" into "eqs. (...)" when I refer to parent numbers instead of individual equation numbers. Unfortunately, this does not seem to be implemented by default, or at least there is no \crefformat{parentequation} or \crefformat{subequation} available.

A short example:

\documentclass{article}

\usepackage{amsmath}
\usepackage{cleveref}

\crefformat{equation}{#2eq.~(#1)#3}
\Crefformat{equation}{#2Eq.~(#1)#3}

\begin{document}

\begin{subequations} \label{parenteq}
\begin{align}
x + y = z \label{subeq1} \\
a + b = c \label{subeq2}
\end{align}
\end{subequations}

\Cref{parenteq} consist of \cref{subeq1} and \cref{subeq2}.

\end{document}


I would like to see the output

Eqs. (1) consist of eq. (1a) and eq. (1b).

Eq. (1) consist of eq. (1a) and eq. (1b).

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Welcome to TeX.sx! A tip: You can use backticks  to mark your inline code as I did in my edit. – doncherry Nov 22 '11 at 14:20

As a workaround you may define a plural equation label:

\documentclass{article}

\usepackage{amsmath}
\usepackage{cleveref}

\crefname{pluralequation}{eqs.}{eqs.}
\Crefname{pluralequation}{Eqs.}{Eqs.}

\crefformat{equation}{#2eq.~(#1)#3}
\Crefformat{equation}{#2Eq.~(#1)#3}

\begin{document}

\begin{subequations} \label{parenteq}\label[pluralequation]{parenteqs}
\begin{align}
x + y = z \label{subeq1} \\
a + b = c \label{subeq2}
\end{align}
\end{subequations}

\Cref{parenteqs} consist of \cref{subeq1} and \cref{subeq2}.

\end{document}


If \crefname is not enough, you may use \crefformat and \Crefformat to define a pluralequation format in the same kind you've done with equation, e.g.;

\crefformat{pluralequation}{#2eqs.~(#1)#3}
\Crefformat{pluralequation}{#2Eqs.~(#1)#3}

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Is it also possible to include the parenthesis '( )' into the output? \crefname does not seem to accept arguments like \crefformat does. – Patrick G. Nov 22 '11 at 17:36
@Patrick G.: You may use \crefformat to define a format of pluralequation, e.g. \Crefformat{pluralequation}{#2Eqs. (#1)#3}. See my change above. – Schweinebacke Nov 22 '11 at 17:45
This works. Do you use the label \label{parenteq} twice on purpose? I think I dont understand how your workaround is supposed to function. – Patrick G. Nov 22 '11 at 18:14
@Patrick G.: If used two different labels parenteq and parenteqs. So you can still reference the singular with \cref{parenteq}. BTW: Using a plural format has been described at the cleveref` manual even. – Schweinebacke Nov 22 '11 at 18:36
Oh well, it seems to work anyway! – Patrick G. Nov 22 '11 at 19:19