Some systems are said to not obey the superposition principle. This is because certain relations are found which are not arrived at by simple addition or subtraction. However, I wonder if some "non-linear systems" can be modeled directly from an underlying set of linear equations. Now, I don't assume that such a set of equations would be finite. One must somehow generate such equations, though not necessarily by using a system of non-linear equations. Is it possible? If so, can such a process theoretically apply to all non-linear systems?