Setup and Rule Diagrams

[Dave Killoran]

Setup and Rule Diagram Explanation

This is a Grouping: Undefined game.

At first this game appears to be a fairly standard Grouping game, but the test makers throw a slight twist into the mix with the last rule that specifies the number of Os selected. Fortunately, this is the only numerical rule, and thus it is easy to remember throughout the game.

Because there is no specified number of fish selected, there is no representation for the group.

The seven rules can be diagrammed as follows:

D02_Game_#4_setup_diagram 1.png

Because of the large number of rules, there are also a large number of inferences:

D02_Game_#4_setup_diagram 2.png

Two additional notes:

• 1. In the rule diagrams, the fifth and sixth rules were combined to create the double-arrow representation, which perfectly captures the relationship between O and P.
  
  2. J and L are both randoms, which in an Undefined game means that their appearance has no effect unless a number is specified for the group. Hence, your focus in this game should be almost entirely on K, M, N, O and P.

Here is the complete setup for the game:

D02_Game_#4_setup_diagram 3.png

[Echx73]

On this question there are a whole host of rules which allows multiple inferences to be made. Your book LG Setup Encyclopedia on page364 shows that if there is P there cannot be K and vice-versa. How can one infer this? Thank you!

Eric

[Dave Killoran]

Hi Eric,

Thanks for the question! That inference is drawn from combining the first and sixth rules:

• First rule: K O
  
  Contrapositive of the sixth rule: O P
  
  Combined: K O P

When that is reduced, it turns into K P. This inference ultimately means that K and P cannot be selected together.

Please let me know if that helps. Thanks!

[annabelle.swift]

2. J and L are both randoms, which in an Undefined game means that their appearance has no effect unless a number is specified for the group. Hence, your focus in this game should be almost entirely on K, M, N, O and P.

Hi! Can someone explain the bolded sentence a bit more?

Does it mean that selecting randoms in an Undefined game does not restrict which other variables can be selected unless a local rule specifies a group size?

[Rachael Wilkenfeld]

Exactly Annabelle! As randoms, J and L can either be in or out without impact on the other rules of the game. We'd need group size information before we could make any deductions about the presence/absence of randoms. In undefined games, we don't have any information restricting group size in the scenario and rules.