CREATE TABLE mountain (id NUMBER, name CLOB, height NUMBER, prominence NUMBER, range CLOB, country CLOB)
CREATE TABLE camera_lens (id NUMBER, brand CLOB, name CLOB, focal_length_mm NUMBER, max_aperture NUMBER)
CREATE TABLE photos (id NUMBER, camera_lens_id NUMBER, mountain_id NUMBER, color CLOB, name CLOB)

Show the name and prominence of the mountains whose picture is not taken by a lens of brand 'Sigma'.
SELECT name, prominence FROM mountain EXCEPT SELECT T1.name, T1.prominence FROM mountain AS T1 JOIN photos AS T2 ON T1.id = T2.mountain_id JOIN camera_lens AS T3 ON T2.camera_lens_id = T3.id WHERE T3.brand = 'Sigma'
SELECT "name", "prominence" FROM "mountain" EXCEPT SELECT "T1"."name", "T1"."prominence" FROM "mountain" "T1" JOIN "photos" "T2" ON "T1"."id" = "T2"."mountain_id" JOIN "camera_lens" "T3" ON "T2"."camera_lens_id" = "T3"."id" AND "T3"."brand" = 'Sigma'