At: lang inters union
Alph:Type, L,M,N:LangOver(Alph). (L 
(M U N)) = ((L M) U (L N))
By:
Unfold `languages` 0
THEN
Unfold `lang_eq` 0
THEN
Unfold `lang_union` 0
THEN
Unfold `lang_inters` 0
THEN
UnivCD
THEN
Reduce 0
THEN
ProveProp
Generated subgoals:None
About:
