CREATE TABLE architect (id TEXT, name TEXT, nationality TEXT, gender TEXT)
CREATE TABLE mill (architect_id DECIMAL, id DECIMAL, location TEXT, name TEXT, type TEXT, built_year DECIMAL, notes TEXT)
CREATE TABLE bridge (architect_id DECIMAL, id DECIMAL, name TEXT, location TEXT, length_meters DECIMAL, length_feet DECIMAL)

How many architects haven't built a mill before year 1850?
SELECT COUNT(*) FROM architect WHERE NOT id IN (SELECT architect_id FROM mill WHERE built_year < 1850)
SELECT COUNT(*) FROM "architect" WHERE NOT "id" IN (SELECT "architect_id" FROM "mill" WHERE "built_year" < 1850)