Representing mathematical equations

[varun7rs at gmail.com]

Hello,

I am working on a mathematical equation which I'm finding really hard to express in python. Could any of you spare some time to help me out?

The equation looks like this

b(i,x) = [Σ(l∈L) [bd(l) * dist(l) * hc(l)]]  / Σ(l∈L) l

I have a problem in representing the above equation. I don't know how to use teh loops over here to express b(i,x)

i,x,l are sets with different numbers

Thank You
I'm sorry if the equation is not expressed in a standard form. I don't have LateX