Hello. I am having difficulties in compiling mutually recursive modules involving classes and instances in GHC 4.08.1. Basicaly I am not finding how to write a .hi-boot where I want to put classes and instances. Consider a program with 3 modules: M1, M2 and Main. The sources are attached to the message. What should go into M2.hi-boot? Would anyone write M2.hi-boot for me so that I can learn it. Thanks. Romildo -- Prof. José Romildo Malaquias <romildo@iceb.ufop.br> Departamento de Computação Universidade Federal de Ouro Preto Brasil