Question: I am attempting to typeset a notation that I use for my own work, and I am struggling to create flexible commands. The notation involves placing mathematical symbols and expressions as if on the vertices of a triangular grid, and then using these objects in equations, resulting in images like these:

![notation](https://i.stack.imgur.com/LZUnj.png)

![notation1](https://i.stack.imgur.com/sXrxz.png)

![notation2](https://i.stack.imgur.com/G2av5.png)

![notation3](https://i.stack.imgur.com/WeAAK.png)

Until now I have been fiddling with `tikzpicture` and painstakingly adjusting node positions until it looks right, but I want to create some commands or a package that would allow me to select the structure, like `twoOverThree` in the fourth image, and input the arguments `{a}{b}{c}{d}{e}` whether they are single letters or slightly more complicated expressions. Any advice? The `tikzpicture` strategy failed to work generally because adjustments in node positioning were always necessary depending on the arguments.

Answer: 
All this notation can be replicated with simple `arrays`, why do you need `TikZ`?

```
\documentclass{article}
\usepackage{amsmath,array}

\newcommand{\twooverthree}[5]{
    \begin{array}{@{}c@{}c@{}c@{}c@{}c@{}}
        &#1&&#2\\
        #3&&#4&&#5
    \end{array}}

\newcommand{\twooverone}[3]{
    \begin{array}{@{}c@{}c@{}c@{}}
        #1&&#2\\
        &#3
    \end{array}}

\newcommand{\oneovertwo}[3]{
    \begin{array}{@{}c@{}c@{}c@{}}
        &#1\\
        #2&&#3\\
    \end{array}}

\newcommand{\oneone}[2]{
    \begin{array}{@{}c@{}c@{}}
        #1\\
        &#2\\
    \end{array}}

\begin{document}
\[
\left(\oneone{a}{b}\right)\left(\oneone{d}{e}\right)
\]

\[
\alpha\left(\twooverone{a}{c}{b}\right) = 
\oneovertwo{\alpha b}{\alpha c}{\alpha a}
\]

\[
\oneone{\oneone{a}{\overline{v}}}{\oneone{\overline{w}}{f}}
\]

\[
\twooverthree{a}{b}{c}{d}{e}
\]
\end{document}

```

![enter image description here](https://i.stack.imgur.com/KLLN0.png)
In order:

1. This can be done using the solution in [this answer](https://tex.stackexchange.com/a/83041/4778). You would need to make line white.
2. You could use matrices here or set a `\newcommand` (I'm working on it).
3. This can be done with a foreach, only two lines of code (I don't know those letters with the above line but you get it):

![enter image description here](https://i.stack.imgur.com/0RClb.png)

```
\documentclass[margin=10pt]{standalone}
\usepackage{tikz}

\begin{document}
\begin{tikzpicture}[x=2mm, y=5mm]

\foreach \y/\letter [count=\x from 0] in {5/a,4/$v$,3/$w$,2/f}{
    \node at (\x,\y) {\letter};
}   

\end{tikzpicture} 
\end{document}

```
4. Same as number 3, can be done in a foreach (maybe even simpler than how I did it):

![enter image description here](https://i.stack.imgur.com/Gj8XB.png) 

```
 \documentclass[margin=10pt]{standalone}
 \usepackage{tikz}

 \foreach \y/\letter [count=\x from 0] in {0/a,1/b,0/c,1/d,0/e}{
 \node at (\x,\y) {\letter};
 }  
 \end{tikzpicture} 
 \end{document}

```