摘要
Let K be a global function field together with a place ∞, and A be the subring of functions regular outside ∞. In this paper we present an effective method to evaluate the (locally free) class number of an arbitrary hereditary A-order in an arbitrary definite central simple K-algebra.We also show that the class number of any nonprincipal genus for a hereditary order in D can be reduced to that of the principal genus for another hereditary order in D.