On Tue, 29 Mar 2022, Mikael Sundqvist via ntg-context wrote:

> On Tue, Mar 29, 2022 at 6:37 AM Otared Kavian <otared@gmail.com> wrote:
> >
> > Hi Mikael,
> 
> Hi Otared,
> 
> >
> > Thanks for your explanation and the example you sent about \definemathsimplealign (I didn’t get immediately that « sesac » in the command \startmathfenced[sesac] means « cases » in reverse or mirrored… I guess this is a wise and humourous choice by Hans :-) ).
> 
> I guess so too :)
> 
> >
> > Regarding \startcases, it seems that it is still not possible to number each equation, but I may be overlooking something. I’ll try a few examples and will let you know, as well as Hans.
> 
> Hm, but a cases environment does not provide several formulas. This is
> just one formula:
> 
> \startformula
> |x|=
> \startcases
> \NC x \NC x>0\NR
> \NC 0 \NC x=0\NR
> \NC -x \NC x<0\NR
> \stopcases
> \stopformula
> 
> and as such should have (at most) one equation number, right?

However, some sub-disciplines like to number each case (for example, if you want to refer to one of them in the future).

> Only Hans knows if it is (easily) doable to add the possibility to add
> numbers to each three lines.

In the old implementation, this was tricky (the equation without the equation number should be centered, and the equation number should be flush right). But I think that this should be possible with the new low-level box alignment macros. 

Aditya