( ( ( A ( red button ) ) ( with ( ( an arrow ) ( pointing ( towards ( ( the chapter ) heading ) ) ) ) ) ) ( ( indicates ( that ( ( the heading ) ( is expandable ) ) ) ) . ) )
(ROOT (S (NP (NP (DT A) (JJ red) (NN button)) (PP (IN with) (NP (NP (DT an) (NN arrow)) (VP (VBG pointing) (PP (IN towards) (NP (NP (DT the) (NN chapter)) (VP (VBG heading)))))))) (VP (VBZ indicates) (SBAR (IN that) (S (NP (DT the) (NN heading)) (VP (VBZ is) (ADJP (JJ expandable)))))) (. .)))
A red button with an arrow pointing towards the chapter heading indicates that the heading is expandable.
(ROOT (S (NP (JJ Reversible) (NNS reactions)) (VP (VBP are) (VP (VBN indicated) (PP (IN by) (NP (NP (JJ opposite-headed) (NNS kinds)) (PP (IN of) (NP (NNS arrows))))))) (. .)))
Reversible reactions are indicated by opposite-headed kinds of arrows.