I don’t understand what your tree is trying to show.
However, I think my explanation above shows why world’s (1a) and (1b) are weighted less than (2) through (5) - they both come from parent world (1). If you gave (1a) and (1b) weight=1, you would be giving parent world 1 weight=2.
I don’t get what your saying… see my probability tree diagram and tell me why you are weighting them differently?
I don’t understand what your tree is trying to show.
However, I think my explanation above shows why world’s (1a) and (1b) are weighted less than (2) through (5) - they both come from parent world (1). If you gave (1a) and (1b) weight=1, you would be giving parent world 1 weight=2.