Say I have a graph G and I want to sum some constant C (like the minimum degree of the graph) for every vertex. Can I use the following notation? $$\sum_{x \in V(G)}C $$
Is this an appropriate way to use sigma notation? There is a similar question here Notation of the summation of a set of numbers but it doesn't account for the fact that the expression could be a constant. A person I am working with questioned it and I couldn't find any resources where it is used in this manner. I don't see why it would be improper because you could have an expression like $\sum_{i=1}^{n}C$. Thank you
Indeed, you are correct, you can use $\sum_{x \in S} C$ for any set $S$ and constant $C$, and since $C$ does not depend on $x$, this simplifies to $$ \sum_{x \in S} C = C \cdot |S|, $$ for any finite set $S$.