
<interactive>:10:1: error:
    • No instance for (Show a1) arising from a use of ‘print’
      Cannot resolve unknown runtime type ‘a1’
      Use :print or :force to determine these types
      Relevant bindings include it :: a1 (bound at <interactive>:10:1)
      These potential instances exist:
        instance Show Ordering -- Defined in ‘GHC.Show’
        instance Show TyCon -- Defined in ‘GHC.Show’
        instance Show a => Show (List1 a) -- Defined at Test.hs:11:12
        ...plus 29 others
        ...plus 13 instances involving out-of-scope types
        (use -fprint-potential-instances to see them all)
    • In a stmt of an interactive GHCi command: print it