LaTeX: stack three lines in math mode

Question

Hey,
I'm writing a formula with three indexes i,j,k.
At the end of the line I'd like to put this:

i=1,...,a
j=1,...,b
k=1,...,n

But I'd like it in smaller font and stacked above each other. Can someone tell me a command which can accomplish this? \mbox can't do math mode, I think.

Answer 1

Try the \substack command:

z_i = a_j + b_k \qquad \substack{
i=1,\dots,a \\
j=1,\dots,b \\
k=1,\dots,n}