StarCraft2: MULE - can he work on one mineral patch with another SCV in parallel?

http://wiki.teamliquid.net/starcraft2/Calldown:_MULE

Also, MULEs can mine over other SCVs

What this means? Does it mean that MULE and SCV can work on one mineral patch in the same time?

Thanks.

P.S. I've tried to look on that during game, but can' figure out.

Yes, that's precisely what it means - a mule can mine a mineral patch which is already being mined by 3 SCVs (which is the maximum number of SCVs on a single patch). Consequently, mules can increase the mineral income even for expansions already completely saturated (24 SCVs on minerals).

Two mules can't mine from the same patch, by the way.