value of 0 log0 in entropy formula Why is the value of $p_i\log(p_i)$ in entropy formula considered $0$ when $p_i =0$? I get that it is the limiting value, but does that mean $p$ is never equals to zero, but only tends to?
Two possible answers:

If a symbol has probability zero, then it does not influence the calculation and there is no need to include it, so you never actually calculate $0\log(0)$.

If you insist in including symbols with zero probability, then $0\log(0)=0$ by convention.