This paper is concerned with the problem of classifying tuples natural numbers a1,…,aK and b1,…,bL such that ratio factorials ∏i=1K(ain)!∕∏j=1L(bjn)! an integer for all n. A complete solution to this only known in case L−K=1, due work Bober building on observation Rodriguez Villegas, which relies Beukers–Heckman classification algebraic hypergeometric functions. We provide alternative proof res...