tcfail019.hs:19:
- No instance for: `B [a]'
- arising from an instance declaration, at tcfail019.hs:19
- Available context: (B [a], C [a])
- From the superclasses of the instance declaration
+ Could not deduce `C [a]'
+ (arising from an instance declaration at tcfail019.hs:19)
+ from the context ()
+ Probable cause: missing `C [a]' in instance declaration context
+ or missing instance declaration for `C [a]'
+ When checking the superclasses of an instance declaration
tcfail019.hs:19:
- No instance for: `C [a]'
- arising from an instance declaration, at tcfail019.hs:19
- Available context: (B [a], C [a])
- From the superclasses of the instance declaration
+ Could not deduce `B [a]'
+ (arising from an instance declaration at tcfail019.hs:19)
+ from the context ()
+ Probable cause: missing `B [a]' in instance declaration context
+ or missing instance declaration for `B [a]'
+ When checking the superclasses of an instance declaration
Compilation had errors