anchor.diff:      let inline nth i arr = Array.get arr i
       let inline setAt i v arr = Array.set arr i v; arr
   
  +    /// Returns the only element of the array for which the given function returns true.
  +    let inline findExactlyOne (predicate : 'a -> bool) (source:'a[]) : 'a =
  +        source |> Array.filter predicate |> Array.exactlyOne
  +
       let copyTo sourceStartIndx startIndx source target =
           let targetLength = (Array.length target)
           if startIndx < 0 || startIndx > targetLength - 1 then
  
positive.code:     let inline cons hd tl = hd::tl
    
      let inline singleton x = [x]
  
      let inline lift2 f (l1: _ list) (l2: _ list) = 
          [ for i in l1 do
  
negative.code:     /// <param name="l">Sequence</param>
      let tryFindWithIndex pred l =
          l |> index |> Seq.tryFind (fun (_,v) -> pred v)
  
      /// Returns the only element of the sequence for which the given function returns true.
      let inline findExactlyOne (predicate : 'a -> bool) (source:seq<'a>) : 'a =
          source |> Seq.filter predicate |> Seq.exactlyOne
  
      let inline lift2 f l1 l2 = 
          seq {
  