Support for persistent newcommand definitions

[alecjacobson]

The following works as expected:

# README 

$\newcommand{\f}{\mathbf{f}}
\|\f\|^2$

But if I put newcommand in a different line this will not work:

# README 

$\newcommand{\f}{\mathbf{f}}$

$\|\f\|^2$

Mathjax for example will keep commands persistent through the document. This is very useful if I want to define some macro at the top of the document and use it in a bunch of equations below.

I humbly request this feature.

[rarora7777]

I agree. This will be very useful.