Typo fix

bf.ml

@@ -40,13 +40,13 @@ and string_of_command = function
   | Shift 1            -> ">"
   | Shift -1           -> "<"
   | Shift n when n < 0 -> "(<" ^ string_of_int (-n) ^ ")"
-  | Shift n            -> "(+" ^ string_of_int n ^ ")"
+  | Shift n            -> "(>" ^ string_of_int n ^ ")"
   | Add 1              -> "+"
   | Add -1             -> "-"
   | Add n when n < 0   -> "(-" ^ string_of_int (-n) ^ ")"
   | Add n              -> "(+" ^ string_of_int n ^ ")"
   | Set n              -> "(=" ^ string_of_int n ^ ")"
-  | Mul (x, y)         -> "(>" ^ string_of_int x ^ "*" ^ string_of_int y ^ ")"
+  | Mul (x, y)         -> "(*" ^ string_of_int x ^ "," ^ string_of_int y ^ ")"
   | Out                -> "."
   | In                 -> ","
   | Loop p             -> "[" ^ string_of_program p ^ "]"