user: Question: Which Works number has a Builder of Avonside Engine Company, and a Type of 4-6-0, and a Number smaller than 12, and a Date of December 1871?
Columns: ['Number', 'Builder', 'Type', 'Date', 'Works number']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'Avonside Engine Company', '4-4-0', 'September 1870', '808']
SQL:

assistant: SELECT "Works number" FROM "Table" WHERE "Builder" = 'Avonside Engine Company' AND "Type" = '4-6-0' AND "Number" < 12.0 AND "Date" = 'December 1871';