( ( The ( sort ( indication arrow ) ) ) ( ( has ( moved ( from ( ( the date ) ( heading ( to ( ( the sender ) heading ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN sort) (NN indication) (NN arrow)) (VP (VBZ has) (VP (VBN moved) (PP (IN from) (NP (NP (DT the) (NN date)) (VP (VBG heading) (PP (TO to) (NP (NP (DT the) (NN sender)) (VP (VBG heading))))))))) (. .)))
The sort indication arrow has moved from the date heading to the sender heading.
(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.