A note on the relationship between graphs and information protocols

Information protocols (IP’s) were developed to describe players who learn their social situation by their experiences. Although IP’s look similar to colored multi-graphs (MG’s), the two objects are constructed in fundamentally different ways. IP’s are constructed using the global concept of history, whereas graphs are constructed using the local concept of edges. We give necessary and sufficient conditions for each theory to be captured by the other. We find that the necessary and sufficient condition for IP theory to be captured by MG theory, which we call SE, excludes relevant game situations. Hence, we conclude that IP theory remains a vital tool and cannot be replaced by MG theory.