“…We can postulate instead that the key commutator close into a different Lie algebra. In one space dimension we can have the spin SU(2) group (β = 1) [1,2], the Lorentz group (β = −1) SU(1, 1) [3], the group of Euclidean motions ISO(2) (β = 0) [4], or any three-parameter algebra, or q-algebra [5,6,7,8], which contracts to HW. This postulate thus entails the correspondence principle: when the number and density of points increase without limit in a discrete Hamiltonian system, the limit should be some well-known continuous Hamiltonian system [9,10].…”