Modular forms for Fr [T].

In [2], we introduced a theory of modular forms for triples (k, oo, d); k a global field of finite characteristic, oo a fixed prime of k and de N". Upon setting d = 2, we studied the theory for the analogues of the principal congruence subgroups of SL(2, Z); obtaining the sharpest results when k = ¥r(T) and oo =the point at infinity on P. In this paper we study the theory for (Fr(T), oo, 2) when our group is the analogue of the f ll modular group, SX(2, Z). Thus, our base ring is Fr[!T], which plays the role of Z.