Mal'tsev term t(x,y,z) = xy⁻¹z: residuals 0 in Z and S_3

Exact symbolic verification that the group-theoretic Mal'tsev term t(x,y,z) = xy⁻¹z satisfies both Mal'tsev identities t(x,y,y) = x and t(y,y,z) = z identically. Abelian case (Z as additive group): t(x,y,z) = x − y + z. Sympy:…