Null = 0

Hi all,

Is there a way to notice the difference between the value 0 and Null for Int types?
I thought that Null was something like "Not declared" but it seems to be equal to 0.

In the following two versions of a simple test function, BlitzMax doesn't notice the difference between 0 or Null when I call it with
Test(5)
or Test(5,0)

Function Test(a%, b% = Null)
	If Not b Then b = 10
	Return (a + b)
End Function

or

Function Test(a%, b% = Null)
	If b = Null Then b = 10
	Return (a + b)
End Function