Task: Question Answering
Input (English): Let us take a closer look at what we mean by agreement between the two parse trees. Essentially, if we have two words in the English sentence denoted by i and i', aligned to words j and j' in the parallel Hindi sentence respectively, we can expect a dependency edge between i and i' in the English parse tree to correspond to an edge between j and j' in the Hindi parse tree, and vice versa. For an edge in the English parse tree, we term the corresponding edge or path in the Hindi parse tree as the projection or projected path of the English edge on the Hindi parse tree, and similarly there are projected paths from Hindi to English. The dual decomposition inference algorithm tries to bring the parse trees in the two languages through its constraints. 
 Question: How does enforcing agreement between parse trees work across different languages?
Output (English): we can expect a dependency edge between i and i' in the English parse tree to correspond to an edge between j and j' in the Hindi parse tree dual decomposition inference algorithm tries to bring the parse trees in the two languages through its constraints