Logical Regulatory Graphs
Informally, a Logical Regulatory Graph (LRG) is a directed labelled multigraph representing interactions (the edges) between genes (the nodes). Each interaction involves two genes, the source and the target, becoming active whenever its source reaches a given level. The activation level of each gene g is defined by a regulatory function comprising parameters relative to all the source genes of all interactions targeting g.
For a more formal definition see Naldi 2011 or dt 2007.