First of all thanks for your reply, I think you are right that I didn't clearify the things in detail. I am designing the program first in Cadence. For that I am using icfb for compiling, gedit as a editor for writing my code and output of program can see in Virtuoso. Now as I mentioned the code in my previous post, actually I am creating two metal(polygon) layers on exactly same location (both layers x-axis and y-axis are same). Let suppose Layer1 and Layer2 has two layers on same location, obviously when my output come on Virtuoso I can see only one Layer but Layer1 and Layer2 should be behind it which I can't see because of same location. Now what I want is that I can subtract from Layer1 to Layer2 or vise versa so that when my output come on Vituoso it shows only Layer1 not Layer2.
Actually I am desiging first my patterns in Cadence then I have to use E-line(lithography) on Silicon chip to write these patters. I am facing the problem that temporary my layer1 is subtract to other layer2 otherwise on E-line it write both layers that make the chip worse.
Hope I explained in detail if not so then please ask again,