I've just started working in CLIPS. I'm trying to do this simple rule, but i've got no idea how to use logical OR here. I know I could define two rules (one for relative-brother and other one for relative-sister) but I think it's not a point. The rule is: You are a relative of someone, if you are his brother or sister.
(defrule MAIN::siblings-relatives
(is-brother ?x ?y)
(test (or (is-sister ?x ?y))
=>
(assert (is-relative ?x ?y))
(printout t ?x " is relative of " ?y crlf))
CLIPS> (clear)
CLIPS>
(defrule siblings-relatives
(or (is-brother ?x ?y)
(is-sister ?x ?y))
=>
(assert (is-relative ?x ?y))
(printout t ?x " is relative of " ?y crlf))
CLIPS> (assert (is-brother Dave Jim))
<Fact-1>
CLIPS> (assert (is-sister Jane Frank))
<Fact-2>
CLIPS> (run)
Jane is relative of Frank
Dave is relative of Jim
CLIPS> (facts)
f-0 (initial-fact)
f-1 (is-brother Dave Jim)
f-2 (is-sister Jane Frank)
f-3 (is-relative Jane Frank)
f-4 (is-relative Dave Jim)
For a total of 5 facts.
CLIPS>