N.B. You can also use the web version of MatTalX if you do not have Google Chrome or Firefox, or if you are on a cellphone.
Documentation is available via PDF here or on GitHub here, with the latest few versions.
MatTalX uses, most of the time, the same command as LaTeX. An important difference from LaTex is that you can't “build” a symbol in MatTalX (see “Combining symbols" in the table of contents for nuance).
As an example, ≝ is simply \def in MatTalX, but \stackrel{\rm def}{=} in LaTeX.
Since MaTalX converts commands into UTF characters. Some expressions are impossible to build. As an example, x^{x^{x^{x}}} couldn't work since everything has to fit in a line. The same goes for
\frac{\frac{\frac{a}{b}}{c}}{d}, which can't work. If you need an expression like that, you can write x^(x^(x^(x))) and ((a/b)/c)/d, respectively.
Full PDF here.
If you find a bug or have any suggestions, please tell us via GitHub.
MatTalX privacy policy here.
N.B. The video is from MatTalX v 1.5.0