getZDZN function written by Riley

Hello,
In the getZDZN function written by Riley, I am trying to understand how the statement works and what it does. Can someone help?
if (strcmp(ssm(i,j).InputName, input) && strcmp(ssm(i,j).OutputName, output))
disp('Found G')
G = ssm(i,j);

Thanks,
Nitish Agrawal