User blog comment:Boboris02/Analysis of Taranovsky's Ordinal Notation with "standard OCFs."/@comment-25601061-20180113214110/@comment-25601061-20180114153029

C(1,1) = C(C(0,0),C(0,0)), and since 0 < C(0,0), C(1,1) is not a valid term.

As for the other one, it's both valid AND lexicographically smaller than C(C(Ω22+C(Ω2,X),0),0).