( ( ( ( ( ( If ( ( the volume ) ( increases ( while ( ( the temperature ) ( is constant ) ) ) ) ) ) ( , ( ( the pressure ) ( must decrease ) ) ) ) , ) and ) ( ( if ( ( the volume ) decreases ) ) ( ( the pressure ) ( must increase ) ) ) ) . )
(ROOT (S (S (SBAR (IN If) (S (NP (DT the) (NN volume)) (VP (VBZ increases) (SBAR (IN while) (S (NP (DT the) (NN temperature)) (VP (VBZ is) (ADJP (JJ constant)))))))) (, ,) (NP (DT the) (NN pressure)) (VP (MD must) (VP (VB decrease)))) (, ,) (CC and) (S (SBAR (IN if) (S (NP (DT the) (NN volume)) (VP (VBZ decreases)))) (NP (DT the) (NN pressure)) (VP (MD must) (VP (VB increase)))) (. .)))
If the volume increases while the temperature is constant, the pressure must decrease, and if the volume decreases the pressure must increase.
(ROOT (S (PP (IN As) (NP (NN temperature) (NNS increases))) (, ,) (NP (NN volume)) (VP (VBZ increases)) (. .)))