Setup and Rule Diagrams

[ava17]

Quick clarification question, does the last rule mean H can never work on Friday? Thanks!

[Robert Carroll]

ava,

That is true. H working on Friday would require G to work on Saturday, conflicting with the first rule. So an H Not-Law can be placed under Friday, as shown in the diagram in the first post.

Robert Carroll

[yupyup]

Hi! I get we cannot create not laws for F, J, and G since they are in conditional statements. Yet how come we can still create a not law for H under Friday?

[Jeremy Press]

Hi yupyup,

Great question!

The reason we can create a definite Not-Law for H underneath Friday is that there are two basic options for every firefighter in the game: either they work on some day (maximum of two days) or they don't work on any day. If H does not work on any day, then clearly H cannot be scheduled on Friday. If H does work on some day (meaning if you put H anywhere on the line), then H has to be followed on the next day by G, which means H cannot be scheduled on Friday. That means there's no possible circumstance where H can be scheduled on Friday.

With the variables you mentioned, there are possibilities within the conditional logic that allow those variables to be scheduled for Friday. For example, F could be scheduled on Friday under the circumstance in which J does not work. For J and G, there are multiple options where scheduling on Friday is possible.

Notice, then, that it's not just the fact that a variable is included in a conditional rule that determines whether you can create Not-Laws for that variable. It's the broader issue of the possibilities that the conditional rule allows for that make such a determination possible.

I hope this helps!

Jeremy

[yupyup]

Thanks Jeremy! I see it now! So basically because the last rule says that placing H on the schedule requires G to also be placed, we can make an H not law. But since placing G on the schedule doesn't require placing H (and same with F and J -- placing one doesn't require the other) we can't put not laws for any of those variables. Makes sense. Thanks again!!

Hi yupyup,

Great question!

The reason we can create a definite Not-Law for H underneath Friday is that there are two basic options for every firefighter in the game: either they work on some day (maximum of two days) or they don't work on any day. If H does not work on any day, then clearly H cannot be scheduled on Friday. If H does work on some day (meaning if you put H anywhere on the line), then H has to be followed on the next day by G, which means H cannot be scheduled on Friday. That means there's no possible circumstance where H can be scheduled on Friday.

With the variables you mentioned, there are possibilities within the conditional logic that allow those variables to be scheduled for Friday. For example, F could be scheduled on Friday under the circumstance in which J does not work. For J and G, there are multiple options where scheduling on Friday is possible.

Notice, then, that it's not just the fact that a variable is included in a conditional rule that determines whether you can create Not-Laws for that variable. It's the broader issue of the possibilities that the conditional rule allows for that make such a determination possible.

I hope this helps!

Jeremy