Clips - adding new rules dynamically - clips

Question

CLIPS is quite new to me - I have been trying to dig deeply into this language for 2 days.
A question came to my mind, namely: how (if possible) can I create/add new rules dynamically?
I would like to do for example sth like this:
(deftemplate action
(slot prev)
(slot curr)
)
(defrule test
(action (prev ?p))
=>
(defrule test_inner
(action (curr ?p))
=>
(printout t "Result of a newly created rule.")
)
)
Please do not pay special attention to the logic of these rules - it is just an example.
After invoking above presented commands I receive:
[EXPRNPSR3] Missing function declaration for defrule.
ERROR:
(defrule MAIN::test
(action (prev ?p))
=>
(defrule
Is this error, a matter of command syntax or I can not define new rules "dynamically"?

Answer 1

First create a string containing the rule (or any other construct) and then use the build function:
CLIPS>
(deftemplate action
(slot prev)
(slot curr)
)
CLIPS>
(defrule test
(action (prev ?p))
=>
(build (str-cat
"(defrule test_inner
(action (curr " ?p "))
=>
(printout t \"Result of a newly created rule.\")
)"
)
)
)
CLIPS> (reset)
CLIPS> (assert (action (prev move)))
<Fact-1>
CLIPS> (agenda)
0 test: f-1
For a total of 1 activation.
CLIPS> (run)
CLIPS> (rules)
test
test_inner
For a total of 2 defrules.
CLIPS> (ppdefrule test_inner)
(defrule MAIN::test_inner
(action (curr move))
=>
(printout t "Result of a newly created rule."))
CLIPS>