ghc/tests/typecheck/should_fail/tcfail023.stderr

   1
   2 Duplicate or overlapping instance declarations:
   3   tcfail023.hs:10: {A B}
   4   tcfail023.hs:13: {A B}
   5
   6 tcfail023.hs:11:
   7     Couldn't match `B' against `Bool'
   8         Expected type: B
   9         Inferred type: Bool
  10     In the right-hand side of an equation for `op': True
  11
  12 tcfail023.hs:14:
  13     Couldn't match `B' against `Bool'
  14         Expected type: B
  15         Inferred type: Bool
  16     In the right-hand side of an equation for `op': True