[comp.text.tex] How to boldface mathe expressions?

hubert@antares.ucsb.edu (05/26/90)

Hi,What should I do if I want some mathematics symboles be boldface?
Say, I have "..... In $S_{2}$  we can ...."

I have tried to use { \bf In $S_{2}$ we can ..} but it doesn't make the S_{2}
bold face ( under LaTeX).


Thank you.