it points out how inseparable the two are 
(ROOT (S (NP (PRP it)) (VP (VBZ points) (PRT (RP out)) (SBAR (WHADJP (WRB how) (JJ inseparable)) (S (NP (DT the) (CD two)) (VP (VBP are)))))))
(ROOT (S (NP (PRP )) (VP (VBZ ) (PRT (RP )) (SBAR (WHADJP (WRB ) (JJ )) (S (NP (DT ) (CD )) (VP (VBP )))))))