Quantization
Poisson brackets deform to Moyal brackets upon quantization, that is, they generalize to a different Lie algebra, the Moyal algebra, or, equivalently in Hilbert space, quantum commutators. The Wigner-Inonu group contraction of these (the classical limit, ) yields the above Lie algebra.
— Wikipedia on Poisson bracket
2012.09.21 Friday ACHK