Input: Article: Virgil's biographical tradition is thought to depend on a lost biography by Varius, Virgil's editor, which was incorporated into the biography by Suetonius and the commentaries of Servius and Donatus, the two great commentators on Virgil's poetry. Although the commentaries no doubt record much factual information about Virgil, some of their evidence can be shown to rely on inferences made from his poetry and allegorizing; thus, Virgil's biographical tradition remains problematic.

Now answer this question: Is Virgil's biographical tradition easily researched or is it problematic?

Output: problematic

Input: Article: A commonly seen example is the double happiness symbol , formed as a ligature of and referred to by its disyllabic name (simplified Chinese: ; traditional Chinese: ; pinyin: shuangxi). In handwriting, numbers are very frequently squeezed into one space or combined common ligatures include nian, "twenty", normally read as ershi, sa, "thirty", normally read as sanshi, and xi "forty", normally read as "sishi". In some cases counters are also merged into one character, such as qishi ren "seventy people". Another common abbreviation is with a "T" written inside it, for , , wenti ("question; problem"), where the "T" is from pinyin for the second syllable ti . Since polysyllabic characters are often non-standard, they are often excluded incharcter dictionaries.

Now answer this question: What is formed as a ligature?

Output: double happiness symbol

Input: Article: London has been the setting for many works of literature. The literary centres of London have traditionally been hilly Hampstead and (since the early 20th century) Bloomsbury. Writers closely associated with the city are the diarist Samuel Pepys, noted for his eyewitness account of the Great Fire, Charles Dickens, whose representation of a foggy, snowy, grimy London of street sweepers and pickpockets has been a major influence on people's vision of early Victorian London, and Virginia Woolf, regarded as one of the foremost modernist literary figures of the 20th century.

Now answer this question: A more current, 20th century center for London's literary set is located where?

Output:
Bloomsbury