mod165.hs:9:5:
    Ambiguous occurrence ‘A.D1’
    It could refer to either ‘A.D1’,
                             imported from ‘Mod164_A’ at mod165.hs:4:1-20
                          or ‘A.D1’, imported from ‘Mod164_B’ at mod165.hs:5:1-20
exit(1)