Figure 1: The edit graph with match cost (M=0), mismatch cost (X), insertion cost (I), and deletion cost (D). Edges in this graph correspond to the cost you need to ‘pay’ for an insertion (cost \(I\)), deletion (cost \(D\)), or mismatch (cost \(X\)) of a letter. To summarize: when the cost model is given by match cost \(M=-B\), mismatch cost \(X\), insertion cost \(I\), and deletion cost \(D\), the equivalent cost model for global alignment with non-negative costs is given by: