3 Duplicate or overlapping instance declarations
5 imported from module `PrelTup' and defined at tcfail073.hs:7
8 Could not deduce `Eq a'
9 (arising from use of `==' at tcfail073.hs:8)
10 from the context: (Eq (a, b))
11 Probable cause: missing `Eq a' in instance declaration context
12 When checking the methods of an instance declaration
14 Compilation had errors