PageHeader : Funkcialaj Ekvacioj, 38 (1995) 11-19 Title : On an Irreducibility Condition for Title : Hypergeometric Systems AuthorInfo : By AuthorInfo : Toshiaki YOKOYAMA AuthorInfo : (Chiba Institute of Technology, Japan) AuthorInfo : Dedicated to Professor Takasi Kusano on his 60th birthday section : 1. Introduction and results section : 2. Proofs section : References