public static IEnumerable<TResult> Pairwise<TSource, TResult>(
	this IEnumerable<TSource> source,
	Func<TSource, TSource, TResult> resultSelector
)

<ExtensionAttribute>
Public Shared Function Pairwise(Of TSource, TResult) ( 
	source As IEnumerable(Of TSource),
	resultSelector As Func(Of TSource, TSource, TResult)
) As IEnumerable(Of TResult)

public:
[ExtensionAttribute]
generic<typename TSource, typename TResult>
static IEnumerable<TResult>^ Pairwise(
	IEnumerable<TSource>^ source, 
	Func<TSource, TSource, TResult>^ resultSelector
)

[<ExtensionAttribute>]
static member Pairwise : 
        source : IEnumerable<'TSource> * 
        resultSelector : Func<'TSource, 'TSource, 'TResult> -> IEnumerable<'TResult> 

int[] numbers = { 123, 456, 789 };
IEnumerable<int> result = numbers.Pairwise((a, b) => a + b);