You have to check if a number is zero before you divide by it, you need to check if a number is positive before you take its log, you need to check it a set is

You have to check if a number is zero before you divide by it, you need to check if a number is positive before you take its log, you need to check it a set is measurable before you measure it or integrate over it. I don’t really see how any of these are significantly different.