( ( If ( ( ( the ( boiling point ) ) ( of water ) ) ( is ( increased ( when ( ( the ( external pressure ) ) ( is increased ) ) ) ) ) ) ) ( , ( ( then ( decreasing ( the ( external pressure ) ) ) ) ( ( should ( decrease ( the ( boiling point ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN If) (S (NP (NP (DT the) (JJ boiling) (NN point)) (PP (IN of) (NP (NN water)))) (VP (VBZ is) (VP (VBN increased) (SBAR (WHADVP (WRB when)) (S (NP (DT the) (JJ external) (NN pressure)) (VP (VBZ is) (VP (VBN increased))))))))) (, ,) (S (ADVP (RB then)) (VP (VBG decreasing) (NP (DT the) (JJ external) (NN pressure)))) (VP (MD should) (VP (VB decrease) (NP (DT the) (JJ boiling) (NN point)))) (. .)))
If the boiling point of water is increased when the external pressure is increased, then decreasing the external pressure should decrease the boiling point.
(ROOT (S (NP (NNP External) (NN pressure)) (VP (VBZ affects) (NP (NP (DT the) (JJ boiling) (NN point)) (PP (IN of) (NP (NN water))))) (. .)))