  Wilf-Zeilberger pairs are fundamental in the algorithmic theory of Wilf and
Zeilberger for computer-generated proofs of combinatorial identities.
Wilf-Zeilberger forms are their high-dimensional generalizations, which can be
used for proving and discovering convergence acceleration formulas. This paper
presents a structural description of all possible rational such forms, which
can be viewed as an additive analog of the classical Ore-Sato theorem. Based on
this analog, we show a structural decomposition of so-called multivariate
hyperarithmetic terms, which extend multivariate hypergeometric terms to the
additive setting.
