Question: cfls are not closed under intersection?
Answer: Theorem: CFLs are not closed under intersection If L1 and L2 are CFLs, then L1 ∩ L2 may not be a CFL. 3. L1 ∩ L2 = {anbnan | n ≥ 0}, which is known not to be a CFL (pumping lemma). Theorem: CFLs are not closed under complement If L1 is a CFL, then L1 may not be a CFL.