( ( In ( the atmosphere ) ) ( , ( ( ( the pressure ) ( of ( the air ) ) ) ( ( decreases ( with ( increasing altitude ) ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (DT the) (NN atmosphere))) (, ,) (NP (NP (DT the) (NN pressure)) (PP (IN of) (NP (DT the) (NN air)))) (VP (VBZ decreases) (PP (IN with) (NP (VBG increasing) (NN altitude)))) (. .)))
In the atmosphere, the pressure of the air decreases with increasing altitude.
(ROOT (S (NP (NNP Air)) (VP (VBP pressure) (SBAR (S (NP (PRP it)) (VP (VBZ decreases) (PP (IN as) (NP (NN altitude) (NNS increases))))))) (. .)))