Rm. Kashaev et al., STAR-SQUARE AND TETRAHEDRON EQUATIONS IN THE BAXTER-BAZHANOV MODEL, International journal of modern physics A, 8(8), 1993, pp. 1399-1409
Spatially symmetrical Baxter-Bazhanov model's Boltzmann weights are pr
oved to satisfy the tetrahedron equation. The latter is a consequence
of the ''inversion'' and ''star-square'' relations for the Boltzmann w
eight elementary building blocks.