I remember from one of my classes that there's a way to build logical statements using a chart. For example, the top row of the chart will contain something like 00 01 10 11 (I probably used the wrong order) and the same goes for the side row. Then we had to cross off boxes and circle them to make larger boxes, or a row of four boxes (or something along those lines). However, I don't remember what it is or the specifics. My notes are in a disarray and I've already sold my textbook. Does anyone know what this technique is called? And does anyone have bookmarked websites/articles on this technique?