| LagTSource, TResult(IEnumerableTSource, Int32, FuncTSource, TSource, TResult) | Produces a projection of a sequence by evaluating pairs of elements separated by a negative offset. | 
| LagTSource, TResult(IEnumerableTSource, Int32, TSource, FuncTSource, TSource, TResult) | Produces a projection of a sequence by evaluating pairs of elements separated by a negative offset. |