add_four_no_carries = ("4":"0")|("5":"1")|("6":"2")|("7":"3")|("8":"4")|("9":"5");
digits = "1"|"2"|"3"|"4"|"5"|"6"|"7"|"8"|"9";
digits_with_zero = "0" | digits;

add_four_with_carries = ("3":"9")|("2":"8")|("1":"7")|("0":"6");
add_one = ("1":"0")|("2":"1")|("3":"2")|("4":"3")|("5":"4")|("6":"5")|("7":"6")|("8":"7")|("9":"8");
add_one_more = "0":"9";
one_more_digit = "1":"";

number_no_carries = digits_with_zero* add_four_no_carries;
number_with_carries = digits* add_one add_one_more* add_four_with_carries | digits digits_with_zero* add_one add_one_more* add_four_with_carries | one_more_digit add_one_more* add_four_with_carries;
final_number = number_no_carries | number_with_carries;

export PROCESS = Optimize[Invert[final_number]];