RepPolyRule1.hs:11:51: error: [GHC-55287]
    • The argument ‘x’ of ‘f’
      does not have a fixed runtime representation.
      Its type is:
        a1 :: TYPE c0
      Cannot unify ‘rep’ with the type variable ‘c0’
      because it is not a concrete ‘RuntimeRep’.
    • In the first argument of ‘f’, namely ‘x’
      In the expression: f x
      When checking the rewrite rule "f_id"
    • Relevant bindings include
        x :: a2 (bound at RepPolyRule1.hs:11:26)

RepPolyRule1.hs:11:55: error: [GHC-55287]
    • The argument ‘x’ of ‘f’
      does not have a fixed runtime representation.
      Its type is:
        a1 :: TYPE c0
      Cannot unify ‘rep’ with the type variable ‘c0’
      because it is not a concrete ‘RuntimeRep’.
    • In the expression: x
      When checking the rewrite rule "f_id"
    • Relevant bindings include
        x :: a2 (bound at RepPolyRule1.hs:11:26)