From Slavnov–Taylor identities to the ZJ equation

In their work devoted to the proof of the renormalizability of non-Abelian gauge theories in the broken phase, Lee and Zinn-Justin have directly benefited from Slavnov's important contributions. Later generalized in the form of the BRST symmetry, the Slavnov–Taylor identities eventually have led to a remarkable quadratic equation for the renormalized gauge action (sometimes called the Zinn-Justin (ZJ) equation), allowing a completely general proof of renormalizability of non-Abelian gauge theories.