testsuite/tests/quantified-constraints/T15231.stderr


1
2
3
4
5
6
7


T15231.hs:15:10: error:
    • Variable ‘c’ occurs more often
        in the constraint ‘c’ than in the instance head ‘Z a’
      (Use UndecidableInstances to permit this)
    • In the quantified constraint ‘c => Z a’
      In the instance declaration for ‘Z (ECC c a)’