Нормальный алгоритм Маркова

module Calculate = 
    let xs = [| ("%*", "*%");("%|", "%*");("*|", "**");("|*", "t");("t*", "*t");("t%", "%t");
                ("%t", "%v|");("t", "|");("%v", "?d");("?d", "d?");("|d", "d|");("?", "%");("*d", "h");("h*", "oh");
                ("h%", "h");("h", "");("*", "");("d", "|_");("/|", "-k");("k|","kk");("k", "|+");("+|", "|+");("-", "ey");
                ("|e", "e|");("y", "%");("eo", "0o");("e", "");("|_", ".a");("a.", ".a");("..", ".");(".aaaaaaaaaa", "a,.");
                (",a", "a,");(".aaaaaaaaa", "9");(".aaaaaaaa", "8");(".aaaaaaa", "7");(".aaaaaa", "6");(".aaaaa", "5");
                (".aaaa", "4");(".aaa", "3");(".aa", "2");(".a", "1");(".", "0");(",", "");("a", ".a");
                ("o", "p||||||||||");("|p", "p|");("pp", "p");("%", "u");("u+", "u");("u", "_");("|+", "|)+");(")", "(>");
                (">+", "+>");("+", "{");("{", "|");(">>>>>", "=");("|=", "=");("(=", "=");("(", "/");("p=", "=<");
                ("<0", "0<");("<1", "1<");("<2", "2<");("<3", "3<");("<4", "4<");("<5", "5<");("<6", "6<");("<7", "7<");
                ("<8", "8<");("<9", "9<");("<<<<<", "$");("0$", "$0");("1$", "$1");("2$", "$2");("3$", "$3");("4$", "$4");
                ("5$", "$5");("6$", "$6");("7$", "$7");("8$", "$8");("9$", "$9");("=$", ".FIN");("0=", "=0");("1=", "=1");
                ("2=", "=2");("3=", "=3");("4=", "=4");("5=", "=5");("6=", "=6");("7=", "=7");("8=", "=8");("9=","=9");
                ("_>", "");("0>", ">0");("1>", ">1");("2>", ">2");("3>", ">3");("4>", ">4");("5>", ">5");("6>", ">6");
                ("7>", ">7");("8>", ">8");("9>", ">9");("p>", "");("p", ".FIN");("_", ".FIN") |]
 
    let divide str = 
        let rec recdivide (str:string) (acc:string) (count:int) = 
            if count = -1 then str, acc else
            let key = xs |> Array.tryFindIndex(fun x -> str.IndexOf (fst x) <> -1)
            match key with
            |Some(x) -> 
                let from, rep = xs.[x];
                let acc = acc + sprintf " %i: %A (%A => %A)\n" count str (fst xs.[x]) rep 
                let start = str.IndexOf from
                let nstr = str.Substring(0, start) + rep + str.Substring(start + from.Length) 
                if nstr.Contains("FIN") then nstr.Replace("FIN",""), acc else recdivide nstr acc (count+1)
            |None -> str,acc
        recdivide str "" 0
 
module UConvert = 
    let int_ufrom10 (x:int) = 
        let str = x.ToString()
        String.Concat(Array.create x '|')
 
type MainView = XAML<"MainWindow.xaml", true>
 
type MainViewModel() as self = 
    inherit ViewModelBase()    
 
    let first = self.Factory.Backing(<@ self.First @>, 1)
    let second = self.Factory.Backing(<@ self.Second @>, 2)
    let result = self.Factory.Backing(<@ self.Result @>, "")
    let fullresult = self.Factory.Backing(<@ self.FullResult @>, "")
 
    let calculate() = 
        let a = UConvert.int_ufrom10 first.Value
        let b = UConvert.int_ufrom10 second.Value
        let r, fr = (Calculate.divide(a + "/" + b))
        result.Value <-  r 
        fullresult.Value <- fr 
 
    let rescommand = self.Factory.CommandSync(calculate)
 
    member self.ResultCommand = rescommand
    member self.First with get() = first.Value and set(v) = first.Value <- v
    member self.Second with get() = second.Value and set(v) = second.Value <- v
    member self.Result with get() = result.Value and set(v) = result.Value <- v
    member self.FullResult with get() = fullresult.Value and set(v) = fullresult.Value <- v

    let divide str = 
        let rec recdivide (str:string) (acc:StringBuilder) (count:int) = 
            if count = -1 then str, acc.ToString() else
            let key = xs |> Array.tryFindIndex(fun x -> str.IndexOf (fst x) <> -1)
            match key with
            |Some(x) -> 
                let from, rep = xs.[x];
                let acc = acc.AppendLine(String.Format(" {0}: {1} ({2} => {3})",count, str, from, rep))
                let start = str.IndexOf from
                let nstr = str.Substring(0, start) + rep + str.Substring(start + from.Length) 
                if nstr.Contains("FIN") then nstr.Replace("FIN",""), acc.ToString()
                else recdivide nstr acc (count+1)
            |None -> str,acc.ToString()
        let sb = new StringBuilder()
        recdivide str sb 0

    member self.Result with get() = result.Value
    member self.FullResult with get() = fullresult.Value

let second = self.Factory.Backing(<@ self.Second @>, 2)

    let second = self.Factory.Backing(<@ self.Second @>, 3)