PageHeader : Funkcialaj Ekvacioj, 38 (1995) 21-36 Title : The Local Uniqueness of Some Title : Characteristic Cauchy Problems for the Title : First Order Systems AuthorInfo : By AuthorInfo : Hitoshi URYU AuthorInfo : (Miyagi University of Education, Japan) section : 1 Introduction section : 2 Statement of theorems section : 3 Proof of the main theorems section : 4 Change of variables section : 5 Proof of the basic propositions section : 6 Carleman estimates for $\tilde{P}$ section : 7 Proof of the basic theorems section : References