1. The authors believe this theorem is due to E. P. Wigner. 2 h2/2m=l.
2. The authors believe this theorem is due to E. P. Wigner. 2 h2/2m=l.
3. See, for example, D. E. Rutherford, Substilutional Analysis (Edinburgh University Press, Edinburgh, 1948). Young’s scheme proceeds by symmetrization, instead of antisymmetrization as used here.
4. We have departed slightly from the notation in Eq. (9). Formerly the bar was regarded as possibly movable leftwards.
5. R. E. Peierls, Quantum Theory of Solids (Oxford University Press, New York, 1955).