CREATE TEMPORARY TABLE foo (string text);
INSERT INTO foo VALUES
    ('the small but capable man'),
    ('the small and strong but capable man');
SELECT * FROM foo WHERE to_tsvector(string) @@ to_tsquery('small<->but');
SELECT * FROM foo WHERE to_tsvector(string) @@ to_tsquery('small<->capable');
SELECT * FROM foo WHERE to_tsvector(string) @@ to_tsquery('small<2>capable');