mod142.hs:2:21:
    Conflicting exports for ‘x’:
       ‘module Mod142_A’ exports ‘Mod142_A.x’
         imported from ‘Mod142_A’ at mod142.hs:4:1-15
         (and originally defined at Mod142_A.hs:3:1)
       ‘module M’ exports ‘M.x’ defined at mod142.hs:6:1