A Mathematical Foundation for Foundation Paper Pieceable Quilts: http://web.stanford.edu/~mleake/projects/paperpiecing/, via https://www.metafilter.com/191666/Quilters-are-the-best-at-graph-theory
They formalize things by hypergraphs, but I prefer antimatroids (https://en.wikipedia.org/wiki/Antimatroid): a pattern is piecable iff you can slice off one piece at a time by guillotine cuts, eventually slicing everything. The possible slicing orders form an antimatroid, because a piece, once sliceable, remains so until it is sliced. The piecing order is the reverse of a slicing order.
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