T7558.hs:8:18: error:
    • Occurs check: cannot construct the infinite type: a ~ Maybe a
    • In the expression: y
      In the first argument of ‘seq’, namely ‘[x, y]’
      In the expression: [x, y] `seq` True
    • Relevant bindings include
        y :: Maybe a (bound at T7558.hs:8:10)
        x :: a (bound at T7558.hs:8:8)
        f :: T a a -> Bool (bound at T7558.hs:8:1)