Yes, you're right. One gets blind after a fair amount of time staring at all those lines.
Of cause that with the A restrictions there is the only possible B exception. The user can start from tab A, or from tab B. So the requirements run from A to B or from B to A. My possible calculation approach comes from my data model where I write the "business rules". There I have the allow/not allow/need. Now that I'm at the database model, I was just wondering if going further with calcs was the best/good way. Although I prefer by far scripting. On top of that, I have the feeling that there is somewhere a conflicting situation/moment in the requirements. It is just a feeling, can't really put a finger on it (now). Because the requirements are coming "from above" (common temp problem, linked to constant changes), there is not much I can do, unless coming up with the physical proof that it doesn't work. I will start with the zillions and painfully crawl through each possibility, until it comes to a screechy halt (or not). Thanks for answering John, appreciate. JM
