Func<dynamic,bool> interplay between C# and F#

EmitBit.cs

namespace FuncTest {
  using System;

  public class EmitBit {
    public Func<dynamic,bool> Emitter { get; set; }
    public void Emit() { 
      Console.WriteLine("emit was {0}", Emitter("test")); 
    }
  }
}

/*
compiles to -> EmitBit.dll
*/

EmitFunc.fsx

#r "EmitBit.dll"

open FuncTest
open System

let emitbit = new EmitBit()
let dynamicFunc = new Func<obj,bool>(fun o -> o.ToString() = "test")

let nullCheck = function
| null -> "is null"
| _ -> "has func"

emitbit.Emitter <- dynamicFunc

nullCheck emitbit.Emitter |> printfn "emitter %s"

emitbit.Emit()