-tcfail020.hs:11: No instance for: `A [taEp]'
- arising from an instance declaration at tcfail020.hs:11
- When checking superclass constraints of an instance declaration
+tcfail020.hs:11:
+ Could not deduce `A [a]'
+ (arising from an instance declaration at tcfail020.hs:11)
+ from the context: (A a)
+ Probable cause: missing `A [a]' in instance declaration context
+ or missing instance declaration for `A [a]'
+ When checking the superclasses of an instance declaration
+
Compilation had errors
+