I'm not sure whether this is a bug, or just a misunderstanding on my
part. With the code below, I expect to have "Boiling!!!" printed to the
console during the second (run) call. Instead, the detect-boiling rule
fires but the alert-user rule does not. However, the example works as
expected if I replace the modify on the RHS of detect-boiling with a
retract+assert.
(deftemplate thermometer
(declare (slot-specific TRUE))
(slot reading))
(deftemplate water
(slot state))
(defrule detect-boiling
(thermometer {reading > 100})
?b <- (water (state ~boiling))
=>
(modify ?b (state boiling))
)
(defrule alert-user
(water (state boiling))
=>
(printout t "Boiling!!!" crlf)
)
(reset)
(watch all)
(assert (water (state cool)))
(bind ?f (assert (thermometer (reading 98))))
(run)
(modify ?f (reading 105))
(run)
Execution trace:
Jess, the Rule Engine for the Java Platform
Copyright (C) 2008 Sandia Corporation
Jess Version 7.1p1 8/6/2008
==> f-1 (MAIN::water (state cool))
==> f-2 (MAIN::thermometer (reading 98))
<== Focus MAIN
<=> f-2 (MAIN::thermometer (reading 105))
==> Activation: MAIN::detect-boiling : f-2, f-1
FIRE 1 MAIN::detect-boiling f-2, f-1
<=> f-1 (MAIN::water (state boiling))
begin:vcard
fn:Aaron Novstrup
n:Novstrup;Aaron
org:Stottler Henke Associates Inc.
adr;dom:;;1107 NE 45th St;Seattle;WA;98105
email;internet:[email protected]
title:AI Software Engineer
tel;work:206.545.2941
tel;cell:805.701.9786
x-mozilla-html:FALSE
url:www.stottlerhenke.com
version:2.1
end:vcard
