I would like to know how to obtain the Straight ladder layout as defined under 14.2.1 in the breqn package documentation. with the "normal" amsmath environments.

I tried

\documentclass{scrartcl}
\usepackage{amsmath}
\usepackage[utf8]{inputenc}

\begin{document}
\begin{align*}
R &={} &&A + B + C + D
\\
&&&+ E + F
\end{align*}

\end{document}


but the spacing around "=" should be equal and not like this:

A second requirement is, that the resulting equation should get one number. The problem is that equation + split does not even allow more than one & for aligning.

Like one of these, with aligned?

\documentclass{scrartcl}
\usepackage{amsmath}
\usepackage[utf8]{inputenc}
\usepackage{eqparbox}

\begin{document}

\begin{aligned}[b] R =A + B & + C + D \\ & + E + F \end{aligned}

\begin{aligned} R ={} &\eqmakebox[A]{ A } + B + C + D \\ &\eqmakebox[A]{{}+{}}E + F \end{aligned}

\end{document}


How about a combination of equation and alignedat?

\documentclass{scrartcl}
\usepackage{amsmath}
\usepackage[utf8]{inputenc}

\begin{document}
\begin{alignedat}{2}% <- Two pairs of right-/left-aligned columns R & = {} & & A + B + C + D \\ & & & + E + F \end{alignedat}

\end{document}


Thank you very much for the solutions. I realized just now, that my question is not exactly a duplicate of, but gets answered here.

The approach with \hphantom is IMHO the cleanest and nicest one and looks exactly as I wanted it to be.

As one can see in the following example that it is now very intuitive to separate different summands in a term from other terms.

\documentclass{scrartcl}
\usepackage{amsmath}
\usepackage{mathtools}
\usepackage[utf8]{inputenc}

\begin{document}
$$\begin{split} R &= A + B + C + D \\ &\hphantom{{}={}} + E + F \\ &\hphantom{{}={}} + G + H \\ &= A + B + C \\ &\hphantom{{}={}} + D + E \\ &\hphantom{{}={}} + F + G + H \end{split}$$

\end{document}


• +1. This helped me a lot! I noticed that you followed the proposal to launch a Materials Modeling stack exchange, however have not yet "committed" yet. At this point we need all the help we can get, would you mind to help us by committing? area51.stackexchange.com/proposals/122958/… – user1271772 yesterday

You can use a plain split, just moving the equals sign in the first column:

\documentclass{scrartcl}
\usepackage{amsmath}

\begin{document}
$$\begin{split} R ={} & A + B + C + D \\ & + E + F \end{split}$$

\end{document}