#NEXUS

BEGIN NETWORKS;

Network tree1 = ((4#H1)2,(4#H1)3)1;
Network tree2 = ((1,2),(4,3));

END;


BEGIN PHYLONET;

SymmetricDifference tree1 tree2;

END;
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Error at [13,21]: Expected 'tree1' to be a tree but found network with hybrid node.