`\\[length]` is unresolved

[chillcicada]

As a common and universal notation, \\[length] can be used to set line spacing, equal to #v() in typst.

Take the below code as an example:

\begin{align*}
a &= b \\[5pt]
  &= c \\[10pt]
  &= d \\[25pt]
  &= e.
\end{align*}

In latex:

In mitex:

As a solution approach, \\[length] can be parsed as #v(length). Thanks for maintainers.