The Card Number Validation hole will go live in . Why not try and solve it ahead of time?

Rankings: Holes

Reversi in Prolog in chars.

# Golfer Lang Points Chars Time
1st IanUtley Prolog 1,000 172
2nd error256 Prolog 983 175
3rd GrayJoKing 🇦🇺 Prolog 956 180