I’ve found that the result of subtraction with nulls looks like this: null - number = number
It would be cool to know the reason behind it. The issue is that it can be hard to spot this behaviour when the calculations are complex.
Of course there are multiple ways to avoid it manually (removing nulls, GHPython/C# checking for nulls etc.) but maybe it will be cool to consider returning different result
NullSubstraction.gh (4.0 KB)