a/b weights for tensor

[miasik]

As we can see at the picture, we take 1-154 as beta and 155-614 as alpha. Tensors 615-768 are colored as green. Does it mean that the method always take the rest total*(1-a-b) (if it is) as a part of b?
As I understand a+b should be less or equal 1. Am I right? What if I set a=0.6, b=0.6?