# Multiple Alignments in equations

I want to align the equations like this

but all I can get is this

And this is my code:

\begin{alignat*}{2}
&\mathcal{F}^N(t) \subset &&\sigma \{Q_0^N(0), \hat{Q}_1^N(0),     \hat{Q}_2^N(0)\} \vee \sigma \{A^N(s), 0 \leq s \leq t\}\\
&    &&\vee \sigma\{S_{12}^l(s),S_{20}^l,0 \leq s \leq t, l \geq 1\}\\
&    &&\vee \mathcal{N},\\
&(Q_0^N(0), \hat{Q}_1^N(0),\hat{Q}_2^N(0)), && \\
&A^N, && \\
&S_{12}^l, S_{20}^l, l \geq 1 &&
\end{alignat*}


I want to make the \mathcal{F}^N(t) and the following Q_0^N(0), A^N,S_{12}^l to be in the middle, how can I do this?

i'm sure there are other questions like this, but it's easier just to answer with an example.

since all lines after the first three are flush left, forget the "internal" && separators, and use an aligned sub-element. at that point, you may as well use a simple align* rather than alignat*.

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{align*}
&\begin{aligned}
\mathcal{F}^N(t) \subset {} &\sigma \{Q_0^N(0), \hat{Q}_1^N(0),
\hat{Q}_2^N(0)\} \vee \sigma \{A^N(s), 0 \leq s \leq t\}\\
&\vee \sigma\{S_{12}^l(s),S_{20}^l,0 \leq s \leq t, l \geq 1\}\\
&\vee \mathcal{N},
\end{aligned}\\
&(Q_0^N(0), \hat{Q}_1^N(0),\hat{Q}_2^N(0)), \\
&A^N, \\
&S_{12}^l, S_{20}^l, l \geq 1
\end{align*}
\end{document}


You can use the aligned environment to put some aligned equations inside another displaymath environment. Thus, in this case, you can use an align* environment for the left-alignment, and an aligned environment inside that for the first few lines, which acts like one line for the purposes of the outer align* environment.

\begin{align*}
&
\begin{aligned}
\mathcal{F}^N(t) \subset &\sigma \{Q_0^N(0), \hat{Q}_1^N(0), \hat{Q}_2^N(0)\} \vee \sigma \{A^N(s), 0 \leq s \leq t\}\\
&\vee \sigma\{S_{12}^l(s),S_{20}^l,0 \leq s \leq t, l \geq 1\}\\
&\vee \mathcal{N},
\end{aligned}\\
&(Q_0^N(0), \hat{Q}_1^N(0),\hat{Q}_2^N(0)),\\
&A^N,\\
&S_{12}^l, S_{20}^l, l \geq 1
\end{align*}


• the \subset in the first line really needs to be followed by {} to get the correct spacing. – barbara beeton Dec 10 '15 at 20:54

Here are two solutions, one using the \mathrlap command, from mathtools, the other with a plain align* environment and an array. Also replaced \hat with widehat, which fits better the size of uppercase Q:

\documentclass{article}%
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{mathtools}

\begin{document}

\begin{alignat*}{2}
&\mathcal{F}^N(t) \subset {}&&\sigma \{Q_0^N(0), \widehat{Q}_1^N(0), \widehat{Q}_2^N(0)\} \vee \sigma \{A^N(s), 0 \leq s \leq t\}\\
& &&\vee \sigma\{S_{12}^l(s),S_{20}^l,0 \leq s \leq t, l \geq 1\}\\
& &&\vee \mathcal{N},\\
&\mathrlap{(Q_0^N(0), \widehat{Q}_1^N(0),\widehat{Q}_2^N(0)),} && \\
&A^N, && \\
&\mathrlap{S_{12}^l, S_{20}^l, l \geq 1 }
\end{alignat*}

\begin{align*}
&\mathcal{F}^N(t) \subset {}\begin{array}[t]{@{}l}\sigma \{Q_0^N(0), \widehat{Q}_1^N(0), \widehat{Q}_2^N(0)\} \vee \sigma \{A^N(s), 0 \leq s \leq t\}\\
\vee \sigma\{S_{12}^l(s),S_{20}^l,0 \leq s \leq t, l \geq 1\}\\
\vee \mathcal{N},
\end{array}\\
& (Q_0^N(0), \widehat{Q}_1^N(0),\widehat{Q}_2^N(0)),\\
& A^N, \\
& S_{12}^l, S_{20}^l, l \geq 1
\end{align*}

\end{document}