fact: Definition sepBy_f (sep : showM) (ls : T) : showM := match fold (fun s acc => match acc with | None => Some (f s) | Some x => Some (x << sep << f s) end) None ls with | None => empty | Some s => s end.
imports: Coq.Strings.String Coq.Program.Wf Coq.PArith.BinPos Coq.ZArith.ZArith ExtLib.Structures.Monoid ExtLib.Structures.Reducible ExtLib.Programming.Injection ExtLib.Data.Char ExtLib.Data.String ExtLib.Data.Fun ExtLib.Core.RelDec