for all pairs of states 
and 
in the chart, such that
the unit-production relation 
is non-zero.
Then
The first summation is carried out once for each
state 
, whereas the
second summation is applied for each choice of Z, but
only if 
is not itself a unit production,
i.e., 
.
Rationale.
This increments 
the equivalent of times,
accounting for the infinity of surroundings in which Y can occur if
it can be derived through cyclic productions.
Note that the computation of 
is unchanged, since 
already includes an infinity of cyclically generated subtrees for Y,
where appropriate.