+ // If pawn captures backward, add an indication 'b'
+ if (
+ move.appear[0].p == V.PAWN &&
+ (
+ (move.appear[0].c == 'w' && (move.end.x - move.start.x > 0)) ||
+ (move.appear[0].c == 'b' && (move.end.x - move.start.x < 0))
+ )
+ ) {
+ notation += 'b';
+ }