including mathematical formulas in patent description

i'm working on my provisional application, and i would like to include serval mathematical formulas in my patent, to make my description more solid. those are not necessary, but because of the complicity of the invention, i think it can help explains how it works.

it is allowed http://www.uspto.gov/web/offices/pac/mpep/mpep-9020-appx-r.html#d0e319627

However is it advisable? i've tried to look for a few patents with math formulas but didn't find anything, maybe you guys have an example?