Univocalics are compositions where only one vowel can appear,
e.g. 'u'. It is naturally very difficult to compose sensible
sentences but masters of poetry can easily cope with the problem
as the Czech poet Konstantin Biebl once did in the following verse:
V půlkruhu trubců zvuk trub v úlu u trůnu
a zázrak v barvách král kravat arara.