How do I align formulas in a table column?

Question

I found this example in another paper that I want to emulate, if possible:

How do I have a three-column layout like that, where the middle column aligns all the formulas on their first operator? I've looked at various questions/answers related to mixing alignment environments with tables, but nothing I've found seems to work quite like this.

@mickep Yes, I am currently using a tabular, but couldn't get the formulas to align properly. If I split the formulas into two columns of "before" and "after" the operator, they do align but then there's a large gap. Maybe the solution is to somehow configure it not to have that padding? — shader, Mar 30 '22 at 18:16
Maybe try tables - Remove extra space between \pm columns in tabular environment? - TeX - LaTeX Stack Exchange ? — user202729, Mar 30 '22 at 18:28
Welcome to TeX.SX. When you post a question, please provide a "Minimal Working Example" (MWE) that starts with \documentclass, includes all relevant \usepackage commands, ends with \end{document} and compiles without errors, even if it does not produce your desired output. — Sandy G, Mar 30 '22 at 18:45

score 2 · Answer 1 · answered Apr 01 '22 at 01:51

\documentclass{article}
\usepackage{libertine}
\usepackage[libertine]{newtxmath}
\begin{document}

\begin{tabular}{lr@{$\mskip\thickmuskip$}c@{$\mskip\thickmuskip$}ll}
  \multicolumn{2}{l}{\textbf{Serverless  Functions}}  &            & \multicolumn{2}{l}{$\langle f, \Sigma, \mathsf{recv}, \mathsf{step}_f, \mathsf{init} \rangle$} \\
  Functions                       & $F$               & $\coloneq$ & $\cdots$                                                                                       \\
  Function name                   & $f$               & $\in$      & $F$                                                                                            \\
  Internal states                 & $\Sigma$          & $\coloneq$ & $\cdots$                                                                                       \\
  Initial state                   & $\mathsf{init}$   & $\in$      & $F \to \Sigma$                                                                                 \\
  Receive event                   & $\mathsf{recv}_f$ & $\in$      & $v \times \Sigma \to \Sigma$                                                                   \\
  Internal step                   & $\mathsf{step}_f$ & $\in$      & $F \times \Sigma \to \Sigma \times t$ & With  effect $t$                                       \\
  Values                          & $v$               & $\coloneq$ & $\cdots$                              & \textsc{json}, \textsc{http}, etc.                     \\
  Commands                        & $t$               & $\coloneq$ & $\varepsilon$                                                                                  \\
                                  &                   & $\vert$    & $\mathbf{return}(v)$                  &   Return  value                                        \\
\end{tabular}

\end{document}

Thanks; it looks great! Would you mind explaining a little about how it works? — shader, Apr 05 '22 at 21:25
@shader This is just a standard tabular. I recommend you read one of the many resources listed under What are good learning resources for a LaTeX beginner? or if English is not your first language see LaTeX Introductions in languages other than English. — Henri Menke, Apr 06 '22 at 07:05

Zarko · Answer 2 · 2022-04-05T23:29:48.293

A small variation of @Henri Menke answer (+1) with use tabularray package:

\documentclass{article}
\usepackage{libertine}
\usepackage[libertine]{newtxmath}
\usepackage{tabularray}
\begin{document}
    \begin{tblr}{colspec = {l Q[r,$] @{;} Q[l,$] l},
                 rowsep  = 1pt,
                 row{1}  = {font=\bfseries}
                 }
\SetCell[c=2]{l}    Serverless  Functions
    &                  & \SetCell[c=2]{c}

                            \langle f, \Sigma,
                            \mathsf{recv}, \mathsf{step}_f,
                            \mathsf{init} \rangle

                                            &               \
Functions

    & F                 & \coloneq\cdots    &               \
Function name

    & f                 & \in F             &               \
Internal states

    & \Sigma            & \coloneq \cdots   &               \
Initial state

    & \mathsf{init}     & \in F \to \Sigma  &               \
Receive event
    & \mathsf{recv}_f   & \in v \times \Sigma \to \Sigma
                                            &               \
Internal step

    & \mathsf{step}_f   & \in F \times \Sigma \to \Sigma \times t
                                            & With  effect $t$  \
Values
    & v                 & \coloneq \cdots   & \textsc{json}, \textsc{http}, etc.    \
Commands

    & t                 & \coloneq \varepsilon

                                            &               \
    &                   & \vert\quad  \mathbf{return}(v) 
                                            & Return  value \
    \end{tblr}
\end{document}

Edit: Above solution work fine with tabularray newest package version version (after 2021N). For older packages versions, for example as is temporary available in Overleaf, unfortunately doesn't work (since math environment in columns are not yet defined). So, you need to use approach with local defining math environments: for example:

\documentclass{article}
\usepackage{libertine}
\usepackage[libertine]{newtxmath}
\usepackage{tabularray}
\begin{document}
    \begin{tblr}{colspec = {l Q[r] @{;} Q[l] l},
                 rowsep  = 1pt,
                 row{1}  = {font=\bfseries}
                 }
\SetCell[c=2]{l}    Serverless  Functions
    &   & \SetCell[c=2]{c}  $\langle f, \Sigma,
                            \mathsf{recv}, \mathsf{step}_f,
                            \mathsf{init} \rangle$

                                            &               \
Functions
    & $F$               & $\coloneq\cdots$  &               \
Function name
    & $f$               & $\in F$           &               \
Internal states
    & $\Sigma$          & $\coloneq \cdots$ &               \
Initial state
    & $\mathsf{init}$   & $\in F \to \Sigma$&               \
Receive event
    & $\mathsf{recv}_f$ & $\in v \times \Sigma \to \Sigma$
                                            &               \
Internal step
    & $\mathsf{step}_f$ & $\in F \times \Sigma \to \Sigma \times t$
                                            & With  effect $t$  \
Values
    & $v$               & $\coloneq \cdots$ & \textsc{json}, \textsc{http}, etc.    \
Commands
    & $t$               & $\coloneq \varepsilon$
                                            &               \
    &                   & $\vert\quad  \mathbf{return}(v)$
                                            & Return  value \
    \end{tblr}
\end{document}

Which gives the same result as the first MWE, however advantages to define of "math columns" are lost.

New version of tabularray is expected to be available around June (after published of the TeXlive 2022).

Pasting your code directly into a blank Overleaf document using pdfLaTeX and Texlive 2021 produces a ton of errors... — shader, Apr 05 '22 at 21:19
@shader, indeed. Overleaf use old version of the tabullarray package which doesn't support math columns. Sorry. You not mentioned that you use Overleaf. In local installation of LaTeX (MiKTeX or TeXlive) with recent version of tabularray (2022A) works fine. It may be a time to make local installation of LaTeX ... — Zarko, Apr 05 '22 at 23:14

score 0 · Answer 3 · answered May 05 '22 at 21:34

Here's a solution using just the amsmath align environment. The spacing of the mathematical elements in the first line isn't exactly what you were looking for, but perhaps it is adequate.

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{align*}
  &\text{\textbf{Serverless Functions}} ~  &  \qquad &\langle f, \Sigma,
      \text{\textbf{recv}}, \text{\textbf{step}}_f, \text{\textbf{init}} \rangle \\
  &\text{Functions}       & F                      &:=  \cdots                                                                 \\
  &\text{Function name}   & f                      &\in F                                                                      \\
  &\text{Internal states} & \Sigma                 &:= \cdots                                                                  \\
  &\text{Initial state}   & \text{\textbf{init}}   &\in F \rightarrow \Sigma                                                   \\
  & \text{Receive event}  & \text{\textbf{recv}}_f &\in v \times \Sigma \rightarrow \Sigma                                     \\
  & \text{Internal step}  & \text{\textbf{step}}_f &\in F \times \Sigma \rightarrow \Sigma \times t & &\text{With effect $t$}  \\
  & \text{Values}         & v                      &:= \cdots                                       & &\text{JSON, HTTP, etc.} \\
  & \text{Commands}       & t                      &:= \varepsilon                                                             \\
  &                       &                        &| \text{\quad \textbf{return}$(v)$}             & &\text{Return value}
\end{align*}
\end{document}

How do I align formulas in a table column?

3 Answers3