About the extended real line $[-\infty,+\infty]$: but what about $(-\infty)+(+\infty)$?
About hereditary σ-ring: also called σ-ideal.
About topological groups: I guess, only commutative groups appear in this context; really?
- I did think of adding capacities, and not only to this entry. On the other hand I feel we need something more systematic about the whole subject and hence I planned to postpone it. But if you want to add something, please go ahead. Camillo (talk) 23:47, 1 October 2012 (CEST)
Set function. Encyclopedia of Mathematics. URL: http://www.encyclopediaofmath.org/index.php?title=Set_function&oldid=28297