anchor.diff:              }
           go head state |> unsafeOfSeq
   
  -    /// <summary>Combines the two sequences into a list of pairs. The two sequences need not have equal lengths:
  +    /// <summary>Combines the two sequences into a sequence of pairs. The two sequences need not have equal lengths:
       /// when one sequence is exhausted any remaining elements in the other
       /// sequence are ignored.</summary>
       ///
  
positive.code: module NonEmptySeq =
      /// <summary>Builds a non empty sequence from the given sequence.</summary>
      /// <param name="seq">The input sequence.</param>
      /// <returns>Non empty sequence containing the elements of the list.</returns>
      /// <remarks>
      ///   **This function does not check whether the sequence is actually non empty or not.**
      /// 
  
negative.code:     /// <returns>The result sequence.</returns>
      let zip (source1: NonEmptySeq<_>) (source2: NonEmptySeq<_>) = Seq.zip source1 source2 |> unsafeOfSeq
  
      /// <summary>Combines the three sequences into a sequence of triples. The sequences need not have equal lengths:
      /// when one sequence is exhausted any remaining elements in the other
      /// sequences are ignored.</summary>
      ///
  