Re: Unexpected Powerloom truth maintenance behavior....

Another issue I observed:

(defmodule "TEST"

  :includes ("PL-USER"))

(in-module "TEST");;  repeat this if evaluating in STELLA



(clear-module "TEST")

(reset-features)



(defconcept person (?x))

(defrelation alive (?x))

(defrelation spouse ((?x person) (?y person))

  :axioms (symmetric spouse))



(defrelation married ((?x person) (?y person))

    :<=> (and (spouse ?x ?y) (alive ?x) (alive ?y)))



STELLA> (ask (forall ?x ?y (=> (and (spouse ?x ?y) (alive ?x) (alive ?y)) (married ?x ?y))))

:NULL_VALUE

STELLA> (ask (forall (?x person) (?y person) (=> (and (spouse ?x ?y) (alive ?x) (alive ?y)) (married ?x ?y))))

:NULL_VALUE



Shouldnt the above asks work? Is there any error in the asks?



I tried (setq *type-check-strategy* :NONE)



with no change...



Thanks

Srini







--- On Thu, 8/21/08, Srini Ram <[email protected]> wrote:
From: Srini Ram <[email protected]>
Subject: Unexpected Powerloom truth maintenance behavior....
To: [email protected]
Date: Thursday, August 21, 2008, 9:31 AM

(defmodule "TEST"

  :includes ("PL-USER"))

(in-module "TEST")



;(clear-module "TEST")

(reset-features)



(defconcept person (?x))

(defrelation spouse ((?x person) (?y person))

  :axioms (symmetric spouse))



(assert (spouse jack jill))  ; expect (person jack) (person jill) to be also asserted because of  domain of  person 



(ask (person jack))
TRUE                                     
;; as expected



(retract (spouse jack jill))          ;; expect (person jack) to also be retracted by truth maintenance system



(ask (person jack))

TRUE                                    
;; unexpected



Am I missing something.



Thanks

Srini

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