Algorithm 3 Calculate accumulated inbound signal from edges.

functionget_inbound_signal(g, n, r, $\mathit{bootstrap}$)

if $\mathit{bootstrap}\ne \mathit{None}$ then

return $\mathit{bootstrap}$

$s\leftarrow \left[\right]$

for all $\mathrm{edges}\mathrm{in}g.\mathrm{in}\_\mathrm{edge}(n)$ do

$s.\mathrm{append}\left(\mathrm{edge}.\mathrm{signal}\right(r\left)\right)$

if $\mathrm{length}\left(s\right)=1$ then

return $s\left[0\right]$

return $s$