Premise: How to install a drawer slide in a lipped cabinet<br>First of all, you need to empty out the cabinet (the top shelf) and measure it. Now measure the cabinet lip from hinge. Make sure that you measure: the cabinet from the widest part of the hinge, inside of the cabinet, all corners of the cabinet, cabinet height from lip, if you need to install double stacked drawer system.
Hypothesis: You can ignore the corners of the cabinet when measuring.