PT 43, S4, G1 - There are exactly six groups in this year's

by **sgorginian** Mon Oct 12, 2009 4:40 pm

Can someone help me with a constraint.

The game is about a Civic Parade and how they march.

One of the constraints says:
At least two groups march behind the puppeteers but ahead of the musicians.

I took this to mean that there are two empty spots in between. M _ _ P

Answering the questions, I assume that constraint was not set up correctly because the constraint tells you that in fact two groups are behind the puppeteers but not exactly how many are ahead of the musicians, just that they are 'ahead'. So would the correct constraint be M _ _ ---- P ?

same with the other constraint: Exactly one group marches behind the firefighters but ahead of the veterans. I put F _ V but I guess the correct is F _ --- V ??

thanks,
Sevan

by **sgorginian** Mon Oct 12, 2009 4:41 pm

i meant P _ _ M

by **noah** Mon Oct 12, 2009 5:25 pm

First of all, these sorts of rules are discussing the elements that must be in between the two given ones. It'd be as if you'd say: "There is a person who is younger than Dan but older than Mike". That definitely means the person's age is in between the Dan and Mikes' ages. The "but" in those rules acts as an "and".

Secondly, you're right that there's a bit of "wiggle room" in there. With the first rule, it may be only 2 groups in between (P _ _ M), but it may be more (P _ _ _ M, for example). So, one way to note this is: "P _ _ + M". It's very important to differentiate between "exactly" two are between and "at least two", so this is a good issue to raise.

With the second constraint, there is definitely only one group in between, so "F _ V", and we call that a "chunk" in our system. P _ _ + M is also a chunk, though one that's a bit tougher to place at times since it can stretch (though it cannot shrink to be smaller than four elements in total).

Does that help?

by **sgorginian** Wed Oct 14, 2009 6:53 pm

thanks Noah - yes it sure does help.

So would my second notation of P _ _ --- M be the same as P _ _ +M ? (im using a hybrid notation from number line and relative ordering.

sg.

by **noah** Thu Oct 15, 2009 10:32 am

sgorginian Wrote:thanks Noah - yes it sure does help.

So would my second notation of P _ _ --- M be the same as P _ _ +M ? (im using a hybrid notation from number line and relative ordering.

sg.

Oh, that makes a lot of sense. Whatever works for you, stick with it.