-
-tcfail080.hs:11:
- Ambiguous type variable(s) `c'
- in the constraint `Collection c a'
- arising from use of `isempty' at tcfail080.hs:11
-
-Compilation had errors
+tcfail080.hs:11:
+ Ambiguous type variable(s) `c' in the constraint `Collection c a'
+ arising from use of `singleton' at tcfail080.hs:11
+ In the first argument of `isempty', namely `(singleton x)'
+ In the right-hand side of an equation for `q':
+ isempty (singleton x)