has already appeared in one forum or another 
(ROOT (S (VP (VBZ has) (ADVP (RB already)) (VP (VBN appeared) (PP (IN in) (NP (NP (CD one) (NN forum)) (CC or) (DT another)))))))
(ROOT (S (VP (VBZ ) (ADVP (RB )) (VP (VBN ) (PP (IN ) (NP (NP (CD ) (NN )) (CC ) (DT )))))))