G. Sardanashvily, Axiomatic quantum field theory. Jet formalism, arXiv: 0707.4257
Jet formalism provides the adequate mathematical formulation of classical field theory, reviewed in hep-th/0612182. A formulation of QFT compatible with this classical one is discussed. We are based on the fact that an algebra of Euclidean quantum fields is graded commutative, and there are homomorphisms of the graded commutative algebra of classical fields to this algebra. As a result, any variational symmetry of a classical Lagrangian yields the identities which Euclidean Green functions of quantum fields satisfy.