Abstract
A brief introduction into bimodules of
I
I
1
-factors is presented. Furthermore a version of the following result due to M. Pimsner and S. Popa is derived: Let
N=
M
−1
⊂M=
M
0
⊂
M
1
⊂
M
2
⊂…
denote the Jones tower of a
I
I
1
-factor
N⊂M
with finite index. Then the factor obtained by the basic construction from the pair
N⊂
M
n−1
is equal to
M
2n−1
.