How can I define a new command with xparse, something like this:
\NewDocumentCommand\tensorkor{ m >{\SplitList{,}}o >{\SplitList{,}}o }
{
?????
}
that i can execute
$ \tensorkor{T}{^a,_b,_c,^r,^f} $
which should result in a code like this
$ {{{{{T^a}_b}_c}^r}^f} $
This is tricky? I dont get it with ProcessList{#1}