1. If G has no positive cycles and no sources, then f has no fixed points. The second tool is the following. Given two words u, v, we say that u contains v if v can be obtained by deleting some letters in u. For instance, aba contains aa;W Abou-Jaoud�;Frontiers in genetics,2016
2. Network information flow. Information Theory;R Ahlswede;IEEE Transactions on,2000
3. Maximum number of fixed points in regulatory Boolean networks;J Aracena;Bulletin of Mathematical Biology,2008