I'm using Lyx 2.1.4. I'd like to write a bunch of inequalities with an
\iff on the right side. The inequalities should be centered, like this:
<centered inequality1> <=>
<centered inequality2> <=>
The problem with gather is that it only allows one column. If I insert a
gathered environment and add a second column, it doesn't work.
Wouldn't it be simpler if Lyx let users decide the horizontal alignment
on a column-by-column basis? I guess there are technical difficulties in