Update allPairs summary text

src/fsharp/FSharp.Core/array.fsi

@@ -12,7 +12,7 @@ namespace Microsoft.FSharp.Collections
     [<RequireQualifiedAccess>]
     module Array = 
 
-        /// <summary>Builds a new array that contains the cartesian product of the two input arrays.</summary>
+        /// <summary>Returns a new array that contains all pairings of elements from the first and second arrays.</summary>
         /// <param name="array1">The first input array.</param>
         /// <param name="array2">The second input array.</param>
         /// <exception cref="System.ArgumentNullException">Thrown when either of the input arrays is null.</exception>

src/fsharp/FSharp.Core/list.fsi

@@ -12,7 +12,7 @@ namespace Microsoft.FSharp.Collections
     [<RequireQualifiedAccess>]
     module List = 
 
-        /// <summary>Returns a new list that contains the cartesian product of the two input lists.</summary>
+        /// <summary>Returns a new list that contains all pairings of elements from the first and second lists.</summary>
         /// <param name="list1">The first input list.</param>
         /// <param name="list2">The second input list.</param>
         /// <returns>The resulting list of pairs.</returns>

src/fsharp/FSharp.Core/seq.fsi

@@ -14,7 +14,7 @@ namespace Microsoft.FSharp.Collections
     [<CompilationRepresentation(CompilationRepresentationFlags.ModuleSuffix)>]
     module Seq = 
 
-        /// <summary>Returns a new sequence that contains the cartesian product of the two input sequences.</summary>
+        /// <summary>Returns a new sequence that contains all pairings of elements from the first and second sequences.</summary>
         /// <param name="source1">The first sequence.</param>
         /// <param name="source2">The second sequence.</param>
         /// <returns>The result sequence.</returns>