Hello @Jean_Pierre_Traets,

True, I played with the formula itself, of course, and was able to get the result. But what’s especially concerning is the fact that formula calculations turn out to be brittle per se. This time it could be this, next time it could be something else. Therefore you need to remain alert all the time to spot potential problems with one of the much used functional areas.

Another concern, which is in fact quite big, is the unstable effect with values “2-3”, “7-12” and “40-45”. For the former 2 cases it is working one way, for the latter one another way. I tested this and and I know the effect, but is there anything else is that I don’t know? Occasional operator characters, numbers, their combinations? Leading, trailing, in the middle?