Linkage

[Xyloid]

example at the bottom of the page gives the rule
W and X cannot speak consecutively
X must speak third or fifth

you show that W can't be in slot 4, but how can W be in slot 2 shouldn't that be against the rules too?

Bryan

[Dave Killoran]

Hey Bryan,

Thanks for the question. In these problems, you want to carefully consider the meaning of that X notation. To do so, consider that X can be in 3 OR 5. And, if X is in 5, then W could be in 2 (and thus, no Not Law is shown there).

W can never be in 4 because X is always in 3 or 5, and thus W in 4 would always cause W and X to be consecutive.

The key is to consider the possibilities for both W and X. In this case, X has options, and that means more possible placements for W that avoid being consecutive with X.

Please let me know if that helps. Thanks!

[Xyloid]

So I'm looking at it as it can't be W2 if X3 and it is showing that it can't be W4 if X5. because X is going to be an either or. But I do understand that it could be in 2 if X is 5. Or what am I missing? Or am I over complicating this.

[Dave Killoran]

Hi Bryan,

It's not that you are overcomplicating this, it's just that there's a distinction between what's locally true in certain instances and what's globally true at all times.

Not Laws are designed to show globally true facts, namely things that cannot ever occur in a game. So, there is an W Not Law under 4 because W can never go in slot 4 under any circumstances. If we showed a W Not Law under 2, we would be saying that W never goes in slot 2. But, as we discussed previously, W can go in slot 2 in certain circumstances, so we wouldn't want to show a W Not Law there.

Now, what you are pointing out is that in certain situations (X in 3), W cannot go in 2. This is a locally true scenario that is only enacted when X is in 3. The best way to show that separately would be: X3 --> not W2. However, to me, this relationship is already captured by the XW not block.

Please let me know if that helps. Thanks!

[Xyloid]

Click,
That makes sense. Thanks for you help on this David.
Bryan

[Dave Killoran]

Excellent, glad I could help!