Largest palindrome product

eular_4.fs

open System;
let sw = System.Diagnostics.Stopwatch()
sw.Start()
let ispalindrom (x):bool = 
  let s = x.ToString().ToCharArray() |> Array.rev
  (new string(s) = x.ToString())
printfn "%d"  (seq {  
    for x in 899..999 do 
        for y in x..999 do 
            if ispalindrom (x*y) then yield (x*y)
    } |> Seq.max);
sw.Stop()
System.Console.WriteLine("Time elapsed: {0}", sw.Elapsed);