A Boolean tree for the function B1(x1, x2, x3) = (NOT x1) OR (x2 AND x3). Input variables xi are connected by Boolean operators. The OR node is the root of the tree, i.e. its value determines the value of the function represented by the tree.
Karl and Dandekar BMC Bioinformatics 2013 14:306 doi:10.1186/1471-2105-14-306