English: Each blue hyperedge has all tails but one, making them B-arcs. Likewise, each orange edge has all heads but one, making them F-arcs. A BF-graph consists only of these two kinds of directed arcs, such as the one shown.
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Captions
Each blue hyperedge has all tails but one, making them '''B-arcs'''. Likewise, each orange edge has all heads but one, making them '''F-arcs'''. A '''BF-graph''' consists only of these two kinds of directed arcs, such as the one shown.