Split-complex numbers and Dirac <i>bra-kets</i>

We describe the real tessarines or "split-complex numbers" and describe a novel instance where they arise in biomedical informatics.We use the split-complex numbers to give a mathematical definition of a Hyperbolic Dirac Network (HDN) -a hyperbolic analogue of a classical probabilistic graphical model that uses quantum physics as an underlying heuristic.The methods of theoretical physics should be applicable to all those branches of thought in which the essential features are expressible in numbers.