I want to minimize DNF formula which has ~200k products combined into a sum. The depth of that formula is 2 - first level is the OR, and second level is AND for all conjunctions.
I have tried using the Espresso program to minimize it, but it only reduces the number of products from 200k to 50k. Espresso still retains the formula's depth of two, and there isn't an option to go deeper, it only puts "don't care" bits.
Are there any algorithms or techniques for taking a large DNF, and producing a smaller, more managable formula – one that isn't just product of sums, or sum of products?
If there isn't, how should one go about doing such task?