How can I add the elements in the sublists?
For example, if I have the list which is
then, the output that I want is
How can I do this?
I thinks the cleanest way is:
using Esc[[Esc and Esc]]Esc.
If you use it a lot (like me), you can create shortcuts as explained here.
If you want to sum all components (as @image_doctor pointed out too, sorry I missed that)
for both components