Finkelstein, D. & Gibbs, J.M. Int J Theor Phys (1993) 32: 1801. doi:10.1007/BF00979502
We propose a unified description of the known forces. We formulate a quantum relativistic spacetime as a (directed) graph of causal arrows with indefinite Hilbert metric, whose physical meaning is given. The simplest graph whose quantum relativity supports conservation of energy-momentum also supports a semidirect product of the cyclic groups2 and3 and the four-group22. We call these lattice degrees of freedom (permutational) twain, trine, and spin. Quantized22 becomes LorentzSpin(4). Gauged, the energy-momentum and spin groups lead to gravity and torsion, and twain and trine lead toSU2 andSU3. We infer that color is actually trine, and thez component of isospin is twain.