RFC 4158 notation

Dear all,

RFC 4158 section 1.4 defines two notations, "X->Y" and "X(Y)". 
However, they are described with almost identical wording:

    [...]
    if entity H were to issue a certificate to entity K, this is denoted as H->K.
    [...]
    If entity H were to issue a certificate to entity K this can be denoted as K(H).

The section concludes with:

    These notations can be combined to denote complicated certification
    paths such as C(D)->B(C)->A(B).

How is C(D)->B(C)->A(B) different from D->C->B->A?
What is "complicated" about that path, other than the seemingly 
redundant notation?

Niklas