Simon Cousins Israel Tax Solution in F#

FoldedIsraelTaxRates.fs

(* http://www.simontylercousins.netsolution to http://ayende.com/blog/108545/the-tax-calculation-challenge *)

let taxes salary =
    let rates = [
        40230.0m,0.45m;
        21240.0m,0.33m;
        14070.0m,0.3m;
        8660.0m,0.23m;
        5070.0m,0.14m;
        0.0m,0.1m]

    let taxAtRate (tax,remainder) (threshold,rate) =
        let taxable = remainder - threshold
        if taxable > 0.0m 
        then tax + rate * taxable, remainder - taxable 
        else tax,remainder
    List.fold taxAtRate (0.0m, salary) rates |> fst