> If you were to add a NULL block you'd have to deal with things
> like, if you only have a then and else, do you run the else on NULL or do
> you do nothing? If you do nothing, what if you want the null and else to
> be the same, do you add another way to specify that? If you do the else,
> then the else stops making sense since it's sometimes false and sometimes
> not true.
it is only syntax problem.
really we have more than one way to continue execution if one block is skipped
so your are free to define IF's behavior any way, particularly the way it is
defined now.
two-blocks IF is oviously enough to code ANY algorythm
but the three-blocks IF is more adequate to tri-valued BOOL