The 2" drain stub up comes up in the back of the cabinet space. A double wye fitting is used standing straight up. The center branch of the wye is the vent and continues on up and out. Each side branch (going off at an 45 degree angle from the vertical center) turns a 90 degree ell to horizontal and toward the center drain on each side of the sink. Then a p-trap is piped under each basket strainer. This eliminates the two diagonal drain lines to the sink and instead there is a drain line going straight back. I have also seen it where the p-traps were installed flat against the back wall and the drain lines from the basket strainers ran straight back to the p-traps and turned a 90 degree ell down.