theorem compound_symmetry_decomp (J : ℕ) (s_sq g : ℝ) (i j : Fin J) :
compoundSymmetryMatrix J s_sq g i j =
(s_sq - g) * (if i = j then 1 else 0) + g := by
simp only [compoundSymmetryMatrix]
split <;> ringResults 36-46: Conservation Laws and Symmetry Identities