CONTEXTUALITY IN QUANTUM-SYSTEMS

The logic of the EPR argument is applied, not to two particles in a li ne but to one particle in a plane. Contextuality (defined here as a ge neralization of the notion of nonseparability) among commuting observa bles is shown to emerge as a result, i.e. although the two orthogonal coordinates characterizing the position of a particle commute, nonethe less there are states in which these coordinates are not independent, in the sense that the measurement or observation of one of them must h ave an effect on the other.