G>        static long Time(DateTime t)
G>        {
G>            return (((t.Hour * 60) + t.Minute) * 60 + t.Second) * 1000 + t.Millisecond;
G>        }
G>        ...
G>            Console.WriteLine("Ack(3, 11) = {0}  time = {1}", a, Time(ft) - Time(st));
G>

using System;
using System.Diagnostics;

class Program
{
    static int Ack(int m, int n)
    {
        if (m == 0)      return n + 1;
        else if (n == 0) return Ack(m - 1, 1);
        else             return Ack(m - 1, Ack(m, n - 1));
    }

    static void Main(string[] args)
    {
        Stopwatch timer = Stopwatch.StartNew();
        int a = Ack(3, 11);
        Console.WriteLine("Ack(3, 11) = {0}  time = {1}", a, timer.Elapsed);
    }
}

Ack(3, 11) = 16381  time = 00:00:00.8839232

using System;
using System.Diagnostics;

static int Ack(int m, int n)
{
    if (m == 0)      return n + 1;
    else if (n == 0) return Ack(m - 1, 1);
    else             return Ack(m - 1, Ack(m, n - 1));
}

Stopwatch timer = Stopwatch.StartNew();
int a = Ack(3, 11);
Console.WriteLine("Ack(3, 11) = {0}  time = {1}", a, timer.Elapsed);

Ack(3, 11) = 16381  time = 00:00:00.4611239

using System;
using System.Diagnostics;

class Program
{
    static int Ack(int m, int n)
    {
        while (m != 0)
        {
            if (n == 0)
                n = 1;
            else
                n = Ack(m, n - 1);
            m--;
        }

        return n + 1;
    }

    static void Main(string[] args)
    {
        Stopwatch timer = Stopwatch.StartNew();
        int a = Ack(3, 11);
        Console.WriteLine("Ack(3, 11) = {0}  time = {1}", a, timer.Elapsed);
    }
}

<xsl:for-each select="rowset/row">
    <xsl:value-of select="@id"/>
</xsl:for-each>

<xsl:for-each select="rowset/row">
ДГ>>    <xsl:value-of select="@id"/>
ДГ>></xsl:for-each>

<xsl:template name="for-each">
    <xsl:param name="nodeset"/>
    <xsl:if test="count($nodeset)!=0">
            <xsl:call-template name="for-each-body">
                    <xsl:with-param name="node" select="$nodeset[1]"/>
                </xsl:call-template>
                <xsl:call-template name="for-each">
                    <xsl:with-param name="nodeset" select="$nodeset[1]/next-sibling::node()"/>
                </xsl:call-template>
        </xsl:if/>
</xsl:template>

ДГ>>Присваиваются... Один раз.

<xsl:variable name="test" select="1"/>
<xsl:for-each select="/*/objs/r">
    <xsl:variable name="test" select="2"/>  <-------
    ...
</xsl:for-each>
<xsl:value-of select="$test"/>