I was just pointing to an lack of software... I don't say that it should be fixed right away, but I think that some sort of accuracy for calculating areas of this kind should exist... Is region entity that was based on SPLINE technical? If you use curves as references for comparison in routine like I did, I firstly encountered that this lack may lead to all kind of mistakes - when you think it's correct as it's supposed to be you may be fooled by program and moreover someone may rely on this calculations thinking that it's good, but in fact it may produce problems in all kind of aspects and fields this results are used... This is no question is some curve technical, pretty or not, sooner or later you'll find that you may just need such elegance in technical and other aspects and instead of improvement and develop on previous achievements like the one in case of SPLINE (when it was first introduced in CAD), the art of making and managing correctness of calculations in field of production will be questionable...