structure ROOT = 

 struct

 structure Integer = 

 struct

 datatype bit = B0 | B1;

 datatype int = Pls | Min | Bit of int * bit | Number_of_int of int;

 fun pred (Bit (k, B0)) = Bit (pred k, B1)

   | pred (Bit (k, B1)) = Bit (k, B0)

   | pred Min = Bit (Min, B0)

   | pred Pls = Min;

 fun succ (Bit (k, B0)) = Bit (k, B1)

   | succ (Bit (k, B1)) = Bit (succ k, B0)

   | succ Min = Pls

   | succ Pls = Bit (Pls, B1);

 fun plus_int (Number_of_int v) (Number_of_int w) =

   Number_of_int (plus_int v w)

   | plus_int k Min = pred k

   | plus_int k Pls = k

   | plus_int (Bit (k, B1)) (Bit (l, B1)) = Bit (plus_int k (succ l), B0)

   | plus_int (Bit (k, B1)) (Bit (l, B0)) = Bit (plus_int k l, B1)

   | plus_int (Bit (k, B0)) (Bit (l, b)) = Bit (plus_int k l, b)

   | plus_int Min k = pred k

   | plus_int Pls k = k;

 fun uminus_int (Number_of_int w) = Number_of_int (uminus_int w)

   | uminus_int (Bit (k, B0)) = Bit (uminus_int k, B0)

   | uminus_int (Bit (k, B1)) = Bit (pred (uminus_int k), B1)

   | uminus_int Min = Bit (Pls, B1)

   | uminus_int Pls = Pls;

 fun times_int (Number_of_int v) (Number_of_int w) =

   Number_of_int (times_int v w)

   | times_int (Bit (k, B0)) l = Bit (times_int k l, B0)

   | times_int (Bit (k, B1)) l = plus_int (Bit (times_int k l, B0)) l

   | times_int Min k = uminus_int k

   | times_int Pls w = Pls;

 end; (*struct Integer*)

 structure Codegen = 

 struct

 fun double_inc k =

   Integer.plus_int

     (Integer.times_int

       (Integer.Number_of_int

         (Integer.Bit (Integer.Bit (Integer.Pls, Integer.B1), Integer.B0)))

       k)

     (Integer.Number_of_int (Integer.Bit (Integer.Pls, Integer.B1)));

 end; (*struct Codegen*)

 end; (*struct ROOT*)