( ( Heating air ) ( ( will ( ( ( increase ( the pressure ) ) , ) ( while ( ( cooling air ) ( decreases pressure ) ) ) ) ) . ) )
(ROOT (S (NP (VBG Heating) (NN air)) (VP (MD will) (VP (VB increase) (NP (DT the) (NN pressure)) (, ,) (SBAR (IN while) (S (NP (VBG cooling) (NN air)) (VP (VBZ decreases) (NP (NN pressure))))))) (. .)))
Heating air will increase the pressure, while cooling air decreases pressure.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NN gas) (NNS particles)) (VP (VB heat) (PRT (RP up))))) (, ,) (NP (NN pressure)) (VP (VBP increase)) (. .)))