#256 A minor question on negation in recursive query

[chi]

Hi,

I have a minor question on the following program:

:- table win/1.

move(1, 2).
move(2, 1).
move(1, 3).
move(3, 4).

win(A) :- move(A, B), not win(B).

I execute it with

/tmp/xsb-code/XSB/bin/xsb --noprompt --quietload --nobanner --nofeedback -e "example.P, win(A), win([A]), halt."

but get an empty result.

However, I manually calculated and found that the result should contain at least win(3). Did I do something wrong?

[Michael Kifer]

First, you have multiple syntax errors in your command in the "..." part.

It would be useful if you tested the exact things that you include in
your messages.

Second, A is indeed 3, but you are not supposed to get any output, since
you did not include any output statements.

Things like

A=3

yes

are provided only in the interactive mode.

On 12/4/22 9:34 PM, chi wrote:

---

[bugs:#256] https://sourceforge.net/p/xsb/bugs/256/ A minor
question on negation in recursive query

Status: open
Group: wrong answer
Created: Mon Dec 05, 2022 02:33 AM UTC by chi
Last Updated: Mon Dec 05, 2022 02:33 AM UTC
Owner: nobody

Hi,

I have a minor question on the following program:

|:- table win/1. move(1, 2). move(2, 1). move(1, 3). move(3, 4).
win(A) :- move(A, B), not win(B). |

I execute it with

|/tmp/xsb-code/XSB/bin/xsb--noprompt --quietload --nobanner
--nofeedback -e "example.P, win(A), win([A]), halt." |

but get an empty result.

However, I manually calculated and found that the result should
contain at least win(3). Did I do something wrong?

---

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[chi]

Hello Michael,

Thank you very much for your answer!

Is it only for recursive queries with negation that the results cannot be obtained using non-interactive mode?

Could you please tell me what the correct command should be if I want to use non-interactive mode?

[Michael Kifer]

xsb --noprompt --quietload --nobanner --nofeedback -e "[example],
win(A), win(A), writeln('A'=A), halt."

On 12/5/22 3:20 AM, chi wrote:

Hello Michael,

Thank you very much for your answer!

Is it only for recursive queries with negation that the results cannot be obtained using non-interactive mode?

Could you please tell me what the correct command should be if I want to use non-interactive mode?

---

** [bugs:#256] A minor question on negation in recursive query**

Status: open
Group: wrong answer
Created: Mon Dec 05, 2022 02:33 AM UTC by chi
Last Updated: Mon Dec 05, 2022 02:34 AM UTC
Owner: nobody

Hi,

I have a minor question on the following program:
~~~
:- table win/1.

move(1, 2).
move(2, 1).
move(1, 3).
move(3, 4).

win(A) :- move(A, B), not win(B).
~~~
I execute it with
~~~
/tmp/xsb-code/XSB/bin/xsb --noprompt --quietload --nobanner --nofeedback -e "example.P, win(A), win([A]), halt."
~~~
but get an empty result.

However, I manually calculated and found that the result should contain at least win(3). Did I do something wrong?

---

Sent from sourceforge.net because you indicated interest in https://sourceforge.net/p/xsb/bugs/256/

To unsubscribe from further messages, please visit https://sourceforge.net/auth/subscriptions/

[chi]

Hello Michael,

I made a stupid mistake on command, thank you very much for your patient reply.