Expansion of Interesting Segments in Composition Graph. The expansion of interesting segments involves three steps: 1. Coalescing nodes (e.g., a, b, c) linked by interesting edges into a group, 2. Converting interesting nodes (e.g., t picked by user) and groups encompassing interesting nodes (e.g., c, f) into nuclei, i.e., graph expansion focus nodes, and 3. Incrementally expanding all the nuclei. We use the heuristics of connecting all the interesting nodes using as many interesting edges as possible. To achieve this, whenever a newly encountered node is part of a non-nucleus group (e.g., one that contains h, i and j), an additional expansion is also triggered and the whole group are engulfed. The expansion stops when all nuclei are connected or when all nodes in the graph are visited.