prettyPreAcc pp alvl wrap (Fold1 f acc)
  = wrap $ prettyArrOp "fold1" [parens (prettyPreFun pp alvl f), pp alvl parens acc]
prettyPreAcc pp alvl wrap (Fold1 f acc)
  = wrap $ prettyArrOp "fold1" [parens (prettyPreFun pp alvl f), pp alvl parens acc]
prettyPreAcc pp alvl wrap (Fold1 f acc)
  = wrap $ prettyArrOp "fold1" [parens (prettyPreFun pp alvl f), pp alvl parens acc]