##### GENERAL #####

(rule $Unary ($PHRASE) (SimpleLexiconFn (type fb:type.any)))
(rule $Binary ($PHRASE) (SimpleLexiconFn (type (-> fb:type.any fb:type.any))))
(rule $Set ($Unary) (IdentityFn))
(rule $Set ($Unary $Set) (MergeFn and))
(rule $Set ($Binary $Set) (JoinFn forward))
(rule $Set ($Set $Binary) (JoinFn backward))
(rule $ROOT ($Set) (IdentityFn))