Answer the question about the paper after reading it carefully. To evaluate if the Transformer can generalize to other tasks we performed experiments on English constituency parsing. This task presents specific challenges: the output is subject to strong structural constraints and is significantly longer than the input. Furthermore, RNN sequence-to-sequence models have not been able to attain state-of-the-art results in small-data regimes. Question: What is English constituency parsing?

English constitu ency par sing is a natural language processing task that involves breaking down a sentence into its constitu ent parts , such as n oun phrases , verb phrases , and pre ject ive phrases . The goal is to identify the hier arch ical structure of the sentence and the relationships between the different parts of speech . This task is particularly challenging because the output is subject to strong structural constraints and is significantly longer than the input . </s>