user: Question: What is the smallest withdrawn value with a GNRI greater than 172, name of croagh patrick and was rebuilt before 1939?
Columns: ['Class', 'GNRI No.', 'Name', 'BP serial No.', 'Rebuilt', '1958', 'Withdrawn']
Types: ['text', 'real', 'text', 'real', 'real', 'text', 'real']
Sample row: ['S', 170.0, 'Errigal', 5628.0, 1939.0, 'CIÉ 170N', 1965.0]
SQL:

assistant: SELECT MIN("Withdrawn") FROM "Table" WHERE "GNRI No." > 172.0 AND "Name" = 'croagh patrick' AND "Rebuilt" < 1939.0;