Fig. 1
An antichain is a subset of nodes in the graph, such that none of the nodes are pairwise connected with edges or paths. In this illustration, an antichain is composed of nodes {S1,S2,S3,T1,T2,T3} (the green dotted line is drawn as a guide of eye). Although in the same antichain, not all nodes share many neighbours. Nodes {S1,S2,S3} share many successors (they are all connected to nodes M, F), so we join them in a Siblinarity community