Constraint algebra
= Constraint algebra
{title2=$\{\varphi_i,\varphi_j\}=f_{ij}{}^k\varphi_k$}
The <Poisson brackets> of <first-class constraints> close on the constraints. When the constraints are independent and the coefficients are constant, the <Jacobi identity for the Poisson bracket> makes the coefficients <structure constants> of a <Lie algebra>.