breqn

\begin{dmath}[background={red}]
Foreground and background colors for the equation. By default the background
area that is colored is the size of the equation, plus fboxsep. If you need anything
fancier for the background, you’d better do it by defining \eqframe in terms of
\colorbox or \fcolorbox.
431 \define@key{breqn}{background}{\def\eq@background{#1}%
432 \freeze@glue\eqlinespacing \freeze@glue\eqlineskip
433 }
434 % \end{macrocode}
435 % \begin{literalcode}
436 % \begin{dmath}[color={purple}]
437 % \end{literalcode}
438 % \begin{macrocode}
439 \define@key{breqn}{color}{\def\eq@foreground{#1}}
\begin{dmath}[center]
\begin{dmath}[nocenter]
The center option means add leftskip stretch to make the individual lines be
centered; this is the default for dseries.
440 \define@key{breqn}{center}[]{\let\eq@centerlines\@True}
441 \define@key{breqn}{nocenter}[]{\let\eq@centerlines\@False}
442 \let\eq@centerlines\@False
\begin{dgroup}[noalign]
Equation groups normally have alignment of the primary relation symbols across
the whole group. The noalign option switches that behavior.
443 \define@key{breqn}{noalign}[]{\let\grp@aligned\@False}
444 \let\grp@aligned\@True % default
\begin{dgroup}[breakdepth={2}]
Break depth of 2 means that breaks are allowed at mathbin symbols inside two
pairs of delimiters, but not three.
445 \define@key{breqn}{breakdepth}{\eqbreakdepth#1\relax}
\begin{darray}[cols={lcrlcr}]
The cols option only makes sense for the darray environment but we liberally
allow all the options to be used with all the environments and just ignore any
unsensible ones that happen to come along.
446 \define@key{breqn}{cols}{\global\let\@preamble\@empty
447 \darray@mkpream#1\@percentchar
448 }
FORMAT STATUS
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