set dist to findLevenshteinDistance for "sunday" against "saturday"
to findLevenshteinDistance for s1 against s2
    script o
        property l : s1
        property m : s2
    end script
    if s1 = s2 then return 0
    set ll to length of s1
    set lm to length of s2
    if ll = 0 then return lm
    if lm = 0 then return ll

    set v0 to {}

    repeat with i from 1 to (lm + 1)
        set end of v0 to (i - 1)
    end repeat
    set item -1 of v0 to 0
    copy v0 to v1

    repeat with i from 1 to ll
        -- calculate v1 (current row distances) from the previous row v0

        -- first element of v1 is A[i+1][0]
        --   edit distance is delete (i+1) chars from s to match empty t
        set item 1 of v1 to i
        --  use formula to fill in the rest of the row
        repeat with j from 1 to lm
            if item i of o's l = item j of o's m then
                set cost to 0
            else
                set cost to 1
            end if
            set item (j + 1) of v1 to min3 for ((item j of v1) + 1) against ((item (j + 1) of v0) + 1) by ((item j of v0) + cost)
        end repeat
        copy v1 to v0
    end repeat
    return item (lm + 1) of v1
end findLevenshteinDistance

to min3 for anInt against anOther by theThird
    if anInt < anOther then
        if theThird < anInt then
            return theThird
        else
            return anInt
        end if
    else
        if theThird < anOther then
            return theThird
        else
            return anOther
        end if
    end if
end min3