mod110.hs:11:10: error:
    Ambiguous occurrence ‘Eq’
    It could refer to either ‘Prelude.Eq’,
                             imported from ‘Prelude’ at mod110.hs:4:1-14
                             (and originally defined in ‘GHC.Classes’)
                          or ‘M.Eq’, defined at mod110.hs:7:1