CLIPSWIN : Sequence expansion not working OR problem with (+)

[Christine DG]

In http://clipsrules.sourceforge.net/documentation/v624/bpg.htm :

12.18.1 Sequence Expansion and Rules

The following rules illustrate appropriate use of sequence expansion on the LHS of rules.

(defrule good-rule-1
(pattern $?x&:(> (length$ ?x) 1))
(another-pattern $?y&:(> (length$ ?y) 1))
(test (> (+ $?x) (+ $?y)))
=>)

But In CLIPSWIN 6.3, I(ve got the error :

[ARGACCES4] Function + expected at least 2 argument(s)

[Gary Riley]

CLIPS> 
(defrule good-rule-1
(pattern $?x&:(> (length$ ?x) 1))
(another-pattern $?y&:(> (length$ ?y) 1))
(test (> (+ $?x) (+ $?y)))
=>)
[ARGACCES4] Function + expected at least 2 argument(s)

ERROR:
(defrule MAIN::good-rule-1
   (pattern $?x&:(> (length$ ?x) 1))
   (another-pattern $?y&:(> (length$ ?y) 1))
   (test (> (+ $?x)
CLIPS> (set-sequence-operator-recognition TRUE)
FALSE
CLIPS> 
(defrule good-rule-1
(pattern $?x&:(> (length$ ?x) 1))
(another-pattern $?y&:(> (length$ ?y) 1))
(test (> (+ $?x) (+ $?y)))
=>)
CLIPS> (assert (pattern 7 8 9))
<Fact-1>
CLIPS> (assert (another-pattern 1 5))
<Fact-2>
CLIPS> (agenda)
0      good-rule-1: f-1,f-2
For a total of 1 activation.
CLIPS> 

[Christine DG]

COOL !!!
Thank you