When I type
Sum into Mathematica, it also offers
Sum` in the autocomplete dropdown, but when I click the little menu button next to
Sum` it doesn't take me to any help page. I was hoping this was how to create symbolic sums for manipulation, but when I tried to use it, it turned the text
Sum red (instead of the usual black for recognized functions), and I had to restart the kernel before things worked again.
I've read questions such as Meaning of backtick in floating-point literal, but I can't find any reference to how the backtick is used with functions.
What is the meaning of
Sum` or what is the help file that explains it?