LaTeX Convention for displaymath

Question

I'm interested in where the convention for using the backslash-bracket (\[ ... \]) for math display environments originates. I really can't stand slash-bracket notation because most people write it on a single line like so:

\[ f(x) = |x| \],

which makes it difficult to find math equations, even in relatively small documents. I always use equation or displaymath environments because

1. it's much easier to search, especially with LaTeX languageservers, which are designed for use with LaTeX environments;
2. it improves code readability. It's not just my opinion that LaTeX is more readable when it uses displaymath environments; when I share LaTeX code for collaborating on presentations, homework, or research my companions often comment that my code is very clean and easier to read, citing the lack of backslash-brackets as the reason.

Why is the backslash-bracket convention so popular? Is it just due to collective laziness to write a \begin{displaymath} ... \end{displaymath} block?

Answer 1

Welcome to TEX.SE! You can first see this answer.

If you search "displaymath" in texdoc latex2e and you can find in sec 8.5:

Further more if you search "displaymath" in texdoc source2e, you can find that

You can see in LaTeX, \[ mathtext \] is equal to \begin{displaymath} mathtext \end{displaymath}. If you write your source file like this

\[
    mathtext 
\]
\begin{displaymath}
    mathtext
\end{displaymath}

both of them seems clean and can remaind you these are "displaymath".

When you use amsmath package, it redefines \[ mathtext \] as \begin{equation*} mathtext \end{equation*} for numberless equation. (You can see this in amsmath.sty)

Answer 2

I personally almost always type equations in three lines. And I use the shorter form because it's easier.

The main issue you seem to find is that the source file is hard to parse. I would like to mention that many of us work on a setup with reverse search. For instance I use WinEdt + SumatraPDF, where reverse-search can be configured; whenever I want to find an equation I just double-click on the equation and WinEdt opens the right file in the right line.