A Lagrange függvény meg

 I =  ∫^Ω (dx)⁴ {Σ_i=e,p,P,E m_i∙c∙∂_νj_i^(n)ν(x) – (F^(em)_μν(x)∙F^(em)μν(x) + F^(g)_μν(x)∙F^(g)μν(x))/4

      - Σ_i=e,p,P,E q_i∙j_i⁽ⁿ⁾_ν(x)∙A^(em)ν(x) + Σ_i=e,p,P,E g_i∙j_i⁽ⁿ⁾_ν(x)∙A^(g)ν(x)}.