Use the pumping lemma to show that the following languages are not context free.

a. {0ⁿ1ⁿ0 ⁿ1ⁿ| n ≥ 0}

Ab. {0ⁿ#02ⁿ#03ⁿ| n ≥ 0}

Ac. {w#t| w is a substring of t, where w, t ∈ {a, b}^*}

d. {t₁#t₂# · · · #t_k| k ≥ 2, each t_i ∈ {a, b}^*, and t_i = t_j for some i ≠ j}