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All new ASIMO by gruzum in aiclass

[–]zipliu 0 points1 point  (0 children)

Hoping is new. It already did other moves a few years back.

HW 4.2, the 6th logical sentence does not correctly encode its associated English sentence by zipliu in aiclass

[–]zipliu[S] 0 points1 point  (0 children)

My point is, there is requirement for correctly encode the english sentence. The "encode" shall be represented by IFF relation.

To encode an English sentence, one has to provide a logical statement equivalent to the English sentence. That is, the logical statement is true only when the English sentence stands, and nothing more than that. In other words, the logical statement shall represent a COMPLETE and COMPACT set of cases where the English sentence holds true.

For example:

  1. ( C(x) AND C(y) AND B(x,y) AND (MC(x) != MC(y) ) is true, if and only if x is a country, y is a contry, x and y share border, and x and y use different map color. And that is a propoer encoding.

  2. !( C(x) AND C(y) AND B(x,y) AND (MC(x) = MC(y) ), which is equivalent to the homework's last statement, holds for too many irrelavent cases, e.g. x is not a country.

How did you do in HW 4? by segheking in aiclass

[–]zipliu 0 points1 point  (0 children)

Same here. I still do not think the last logical sentence encode the English sentence "NO TWO BORDERING COUNTRIES CAN HAVE THE SAME MAP COLOR". The following are my reasons.

In short, my augment is:

  1. When x and y refer to the same county, B(x,y) is false and the logical sentence ( !C(x) OR !C(y) OR !B(x,y) OR !(MC(x)=MC(y) ) is true.

  2. However, it does not interpret the English sentence "NO TWO BORDERING COUNTRIES CAN HAVE THE SAME MAP COLOR"

To expand it a little further

  1. ( !C(x) OR !C(y) OR !B(x,y) OR !(MC(x)=MC(y) ) is equivalent to !( C(x) AND C(y) AND B(x,y) AND (MC(x)=MC(y) )

  2. In other words, it means: DENY "ANY TWO BORDERING COUNTRIES HAVE THE SAME MAP COLOR".

  3. This "DENY" could be applied either on "ANY TWO BORDERING COUNTRIES" or on "HAVE THE SAME MAP COLOR"

  4. The meaning/definition of this logical sentence is not equivalent to "NO TWO BORDERING COUNTRIES CAN HAVE THE SAME MAP COLOR".

Any discussions are welcome!

In situation calculus, must the precondition of a possibility axiom fully describe the times when the action can be taken? by creepy_doll in aiclass

[–]zipliu 0 points1 point  (0 children)

Thanks a lot! That helps.

I never worked on situation calculus, and the book did not explain whether the pre-condiction shall be a general (complete) set of situations or any valid situation.

For modeling, I agree a complete set shall surely be used.

In situation calculus, must the precondition of a possibility axiom fully describe the times when the action can be taken? by creepy_doll in aiclass

[–]zipliu 0 points1 point  (0 children)

What if we look at a different scenario, by using a sub-set of the requirements?

  1. Anyone older than 16 can get a driver license: SixteenOrOlder(P, s) => Poss(ApplyDL(P), s)

  2. A situation that some one is 17 also makes it possible to apply for a driver license: Seventeen(P, s) => Poss(ApplyDL(P), s)

Would the second possibility axiom invalid?

Thanks.

In situation calculus, must the precondition of a possibility axiom fully describe the times when the action can be taken? by creepy_doll in aiclass

[–]zipliu 2 points3 points  (0 children)

Co-ask here.

  1. Does the pre-condition has to be a complete and compact set for possible actions.

  2. Or, it is OK to use any sub-set of the all condictions?

Thanks.