We show that the celebrated six-vertex model of statistical mechanics (along
    with its multistate generalizations) can be reformulated as an Ising-type model
    with only a two-spin interaction. Such a reformulation unravels remarkable
    factorization properties for row to row transfer matrices, allowing one to
    uniformly derive all functional relations for their eigenvalues and present the
    coordinate Bethe ansatz for the eigenvectors for all higher spin
    generalizations of the six-vertex model. The possibility of the Ising-type
    formulation of these models raises questions about the precedence of the
    traditional quantum group description of the vertex models. Indeed, the role of
    a primary integrability condition is now played by the star-triangle relation,
    which is not entirely natural in the standard quantum group setting, but
    implies the vertex-type Yang-Baxter equation and commutativity of transfer
    matrices as simple corollaries. As a mathematical identity the emerging
    star-triangle relation is equivalent to the Pfaff-Saalschuetz-Jackson summation
    formula, originally discovered by J.~F.~Pfaff in 1797. Plausibly, all vertex
    models associated with quantized affine Lie algebras and superalgebras can be
    reformulated as Ising-type models with only two-spin interactions.}

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