anchor.diff:          static member        instance (Mempty, _:option<'a>) = fun () -> None :option<'a>
           static member        instance (Mempty, _:array<'a> ) = fun () -> [||] : array<'a>
           static member        instance (Mempty, _:string    ) = fun () -> ""
  +        static member        instance (Mempty, _:StringBuilder) = fun () -> new StringBuilder()
           static member        instance (Mempty, _:unit      ) = fun () -> ()
           static member        instance (Mempty, _:Set<'a>   ) = fun () -> Set.empty : Set<'a>
           static member        instance (Mempty, _:Map<'a,'b>) = fun () -> Map.empty : Map<'a,'b>
  
positive.code: 
  type Any = Any of bool with
      static member instance (Monoid.Mempty, _:Any     ) = fun () -> Any false
      static member instance (Monoid.Mappend,  Any x, _) = fun (Any y) -> Any (x || y)
negative.code: namespace FsControl.Core.Abstractions
  
  open System.Text
  open FsControl.Core.Prelude
  
  module Monoid =
  