Level:
Lib
Thy
Top
:
Hypotheses:
None
Conclusion:
Alph:
.
L:L(Alph). (L U L) = L
Applied Tactic:
Unfold `languages` 0 THEN Unfold `lang_eq` 0 THEN Unfold `lang_union` 0 THEN Reduce 0 THEN UnivCD THENW Auto
Generated subgoals:
1
. L l
L l
L l
Alph:
. L:L(Alph). (L U L) = L
L l 
L l