CREATE TABLE table_11856 ("Client" TEXT, "Windows" TEXT, "GNU/Linux" TEXT, "Mac OS X" TEXT, "Haiku" TEXT)

Which GNU/Linux had no haiku and a client of airdc++?
SELECT "GNU/Linux" FROM table_11856 WHERE "Haiku" = 'no' AND "Client" = 'airdc++'
SELECT "GNU/Linux" FROM "table_11856" WHERE "Client" = 'airdc++' AND "Haiku" = 'no'