Question

why is there a need to use $S_{n}$ and ∑ notation?
(I'll report you if you didn't answer it right!)

Answer 1

Step-by-step explanation:

This book is dedicated to those who worked so hard

and for so long to bring these important tools to us:

The LATEX3 team

and in particular

Frank Mittelbach (project leader) and David Carlisle

The AMS team

and in particular

Michael J. Downes (project leader) and David M. Jone