  We have shown previously that at each stage of Eratosthenes sieve there is a
corresponding cycle of gaps $\mathcal{G}(p_0^\#)$. We can view these cycles of
gaps as a discrete dynamic system, and from this system we can obtain exact
models for the populations and relative populations of gaps $g < 2p_1$ if we
can get the initial conditions from $\mathcal{G}(p_0^\#)$. In this addendum we
have shown that we can produce the model for $g=2p_1$ from these initial
conditions. This model requires one special iteration to track the count from
$\mathcal{G}(p_0^\#)$ to $\mathcal{G}(p_1^\#)$, after which we can use the
general model for these populations. As a specific example we exhibit the model
for the gap $g=82$ using $\mathcal{G}(37^\#)$ for initial conditions.
  We show further that in order to produce the models for $g=2p_1+2$ and beyond
from initial conditions in $\mathcal{G}(p_0^\#)$, we would have to track
subpopulations of the driving terms until the general model applies, that is
until $g < 2p_{k+1}$.
  This work serves as an addendum to the existing references "Patterns among
the Primes" and "Combinatorics of the gaps between primes". We do not duplicate
that background here, beyond summarizing a few needed results.
