I wanted to get all the bipartitions from a tree: tree image

It should give the following bipartitions:

1. A,B,C,D,E,F,G,H
2. A,B,C,D,I,J
3. E,F,G,H,I,J
4. A,B,C,D
5. E,F,G,H
6. A,B
7. C,D
8. E,F
9. G,H
10. I,J

However, when I did the following:

library('ape')    
t = read.tree('((((A,B),(C,D)),((E,F),(G,H))),(I,J));') 
prop.part(t)

or

library('ape')    
t = read.tree('((((A,B),(C,D)),((E,F),(G,H))),(I,J));') 
subtrees(t)

they only gave me the bipartitions 1,4-10, without 2 and 3.

What is the problem here?