The structure of differential graded Lie algebra (dgLa) on the vector space of graphs with a wedge ordering of edges. "Zero graphs" = minus themselves. The vertex-blow-up differential, Lie bracket, its Jacobi identity. The determining properties of the complex (identities involving zero graphs).
* Examples of nontrivial cocycles: the tetrahedron, 5-wheel + prism. The (2k+1)-wheels as markers of nontrivial cocycles originating from the Grothendieck--Teichmueller Lie algebra.