Table: mine_countermeasure_vessel
Columns: navy
name
pennant
commissioned
home_port

Question: What is the home port of m40?
SQL: SELECT "home_port" FROM mine_countermeasure_vessel WHERE "pennant" = 'm40'

Question: What is the navy for middleton with a home port of portsmouth after 1983?
SQL: SELECT "navy" FROM mine_countermeasure_vessel WHERE "home_port" = 'portsmouth' AND "commissioned" > 1983 AND "name" = 'middleton'