I've been using LaTeX for a couple of years, but I'm pretty new to the
tikz package. In particular, I'd like to add Karnaugh's maps in my document. I've already found a solution that satisfy me (can be found here: How would you do Karnaugh's maps in LaTeX or ConTeXt?), and I'd like to slightly adjust it to make the boolean params appear at the very first cell which I want it to be diagonally split like in this example: Remove vertical lines for table.
Would anybody help me? Thanks in advance!