  Quantization of gauge fields by the BRST method requires sources in addition
to fields, and a bilinear anti-bracket defined in terms of them. This bracket
is a sort of generalization of a Poisson bracket in classical mechanics.
Canonical transformations are also generalized as anti-canonical
transformations. In this paper, we take the analogy with classical mechanics
one step further, by showing how anti-canonical transformations can be derived
from generating functions. We give an example relevant to the renormalization
of QCD in the Hamiltonian formalism.
