Abstract: Logic models in analying stability of a system with complexity are applicable to Physics, Chemistry and other areas of sciences. Using the orthogonality and symmetry definited by the theory of multilateral matrices, we present a stable logic model with two causal effects that is sometimes successful in analying stability of a system with complexity. The structure of the logic model is clear and simple and can be easily used to study a lot of complex problems. As an application, some examples are given.