anchor.diff:          registerToR<bool[]>    (fun engine v -> upcast engine.CreateLogicalVector v)
           registerToR<byte[]>    (fun engine v -> upcast engine.CreateRawVector v)
           registerToR<double[]>  (fun engine v -> upcast engine.CreateNumericVector v)
  +        registerToR<DateTime[]> (fun engine v -> upcast createDateVector v)
   
           registerToR<string[,]>  (fun engine v -> upcast engine.CreateCharacterMatrix v)
           registerToR<Complex[,]> (fun engine v -> upcast engine.CreateComplexMatrix v)
  
positive.code:                        | Some res -> res
                         | _ ->  failwithf "No default converter registered from R %s " (sexp.Type.ToString())
          
      do
          registerToR<SymbolicExpression> (fun engine v -> v)
  
  
negative.code:         registerToR<bool>    (fun engine v -> upcast engine.CreateLogicalVector [|v|])
          registerToR<byte>    (fun engine v -> upcast engine.CreateRawVector [|v|])
          registerToR<double>  (fun engine v -> upcast engine.CreateNumericVector [|v|])
          registerToR<DateTime> (fun engine v -> upcast createDateVector [|v|])
          
          registerToR<string[]>  (fun engine v -> upcast engine.CreateCharacterVector v)
          registerToR<Complex[]> (fun engine v -> upcast engine.CreateComplexVector v)
  