public static boolean isBuiltinFunction(LispValue code)
		{
			if ((code == null) || (code == NIL))
				return false;

			if (code instanceof LispSymbol)
				if (code.fboundp())
					code = code.symbol_function();
				else
					return false;
			
			if (code instanceof LispFunction)
				code = ((LispFunction)code).getCode();

			if (code instanceof LispPrimitive)
				return true;
			
			return false;
	  }