Check the rule (Solution)

The D and the 8.

• The D needs to be checked because if there is not a 3 on the other side, the rule is broken.
• The A does not need to be checked because no matter what is on the other side, the rule is fine. The rule only dictates what is on the other side of a D.
• The 3 does not need to be checked. If it’s a D, then great - the rule is followed. If it’s not a D, that’s fine too.
• The 8 needs to be checked. If it’s not a D on the other side, that’s fine. If it is a D on the other side, then the rule has been broken.