30 Use the pumping lemma to show that the following languages are not context free.
a. {0ⁿ1ⁿ0ⁿ1ⁿ n≥0}
b. (0ⁿ#0²ⁿ #0³ⁿ n≥0}
c. (wet w is a substring of t, where w, t ∈ {a,b}}
d. tᵢ#tⱼ#t#tak≥2, each t, ∈ {a,b}", and tᵢ, tⱼ for some i ≠ j}