I want to typeset several equations with only one equation number vertically centered, and every equation horizontally center.
I know two options. One is
aligned environment within
equation, which handles equation number nicely, but the default alignment (without any
&) is right alignment; and you know, you can't rely on
& to force center alignment.
IEEEeqnarray environment, which handles alignment nicely, but the equation numbering of which is somewhat awkward since numbering is processed on a line-to-line basis, as far as I know (if the number of equations is even, or equations take different vertical space, you will be screwed).
Any idea about this? Maybe I missed some functionality of