[GiNaC-list] Indexed vs labelled

[Alejandro Limache]

>Q4. "Indices" of various kinds proved to be useful in different areas of
>mathematics, e.g. linear algebra.

>Q5. I need expressions of the type \sum_{j=1}^n a_j b_j for an unspecified
>symbolic value n and quantities a_j and b_j *labelled* (rememberring that
>_indexed_ is already copyrighted) by j in this range.

I have the same type of concern.