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