( ( If ( ( ( the ( same piece ) ) ( of paper ) ) ( is burned ) ) ) ( , ( it ( ( is ( ( broken up ) ( into ( ( different substances ) ( that ( ( are not ) paper ) ) ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN If) (S (NP (NP (DT the) (JJ same) (NN piece)) (PP (IN of) (NP (NN paper)))) (VP (VBZ is) (VP (VBN burned))))) (, ,) (NP (PRP it)) (VP (VBZ is) (VP (VBN broken) (PRT (RP up)) (PP (IN into) (NP (NP (JJ different) (NNS substances)) (SBAR (WHNP (WDT that)) (S (VP (VBP are) (RB not) (NP (NN paper))))))))) (. .)))
If the same    piece of paper is burned, it is broken up into different substances that are    not paper.
(ROOT (S (NP (NP (DT The) (NN action)) (PP (IN of) (S (VP (VBG burning) (NP (NP (DT a) (NN piece)) (PP (IN of) (NP (NN wood)))))))) (VP (VBZ forms) (NP (DT a) (JJ different) (NN chemical) (NN substance))) (. .)))