Universal Not-Block?

[rwraulynaitis]

Hello!

On page 236 of the 2020 LGB, a sidenote explains that a universal AA not-block is not used in this scenario (unlike the example on page 233) because there are different types of animals. However, aren't there different types of colors (blue, green, white, yellow) in the example on page 233? I am not understanding the difference between the two scenarios, and why a universal not-block should be used for one but not for the other.

Thank you!

[Dave Killoran]

Hi R,

Thanks for the question! On page 233, the CC not-block is used since it can reference any color combination of the same type:

BB
GG
WW
YY

So, any given color pairing is encompassed by that CC not block.

If the AA notation was used in a similar manner on page 236 then it would only outlaw:

LL
TT
ZZ

And it wouldn't include combinations of LT (and technically LZ or TZ either).

In other words, we can use the CC to get across a bigger idea very effectively; but AA would only be partial (and if you tried to make it broader it would get too broad). that's what I was trying to get across there (perhaps not clearly enough ).

Thanks!

[rwraulynaitis]

Hey Dave,

Thanks for the quick reply!

I think I see where you are going, but I am still a little unclear. I understand why an AA not-block would not include the LT combinations, but why would it need to? I figured that the third rule created the LT not-block combinations.

Page 236 says that the second rule creates an LL not-block, a TT not-block, and a ZZ not-block. Isn't that exactly what an AA not-block achieves, as you outlined in your response?

[Dave Killoran]

It's a matter of avoiding some confusion, and the if you combine AA with other specific blocks, to me that creates issues (which I tried to explain but apparently didn't do a great job of ).

However, the good news is that you can represent groupings like this in any way that feels comfortable to you, so if the distinction is clear, then go right ahead with it!