1/2 step down
the little "p"s and "h"s mean hammer-ons and pull-offs.
[ Tab from: http://www.guitartabs.cc/tabs/s/slayer/south_of_heaven_tab_ver_3.html ]
Eb----------------|-|----|---------------|
Bb----------------|-|----|---------------| This means that you play
Gb---------9--8-7-|-|7p6-|-6h7p6h7p6h7p6-| the first part every time,
Db----9-10--10-9-8|-|----|---------------| and play the last two
Ab---7------------|-|----|---------------| every other time.
Eb--0-------------|-|----|---------------|
p.m.
Eb-------------|-|----|---------------|
Bb-------------|-|----|---------------|
Gb-------4-3-2-|-|2p1-|-1h2p1h2p1h2p1-|
Db----2-5-4-3-2|-|----|---------------|
Ab---2---------|-|----|---------------|
Eb--0----------|-|----|---------------|
|