Our approach to FS identification involves optimization of the total explanatory power of a lattice, where each node corresponds to an n-gram type. The explanatory power of the whole lattice is defined simply as a product of the explainedness of the individual nodes. Each node can be considered either "on" (is an FS) or "off" (is not an FS). The basis of the calculation of explainedness is the syntax-sensitive LPR association measure of<cite> Brooke et al. (2015)</cite> , but it is calculated differently depending on the on/off status of the node as well as the status of the nodes in its vicinity.