Cohomology of the tetrahedral complex and quasi-invariants of 2-knots

This paper explores a particular statistical model on 6-valent graphs with special properties which turns out to be invariant with respect to certain Roseman moves if the graph is the singular point graph of a diagram of a 2-knot. The approach uses the technic of the tetrahedral complex cohomology. We emphasize that this model considered on regular 3d-lattices appears to be integrable. We also set out some ideas about the possible connection of this construction with the area of topological quantum field theories in dimension 4.