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(i) $ L = (0^i1^j2^i3^j | i \gt= 0,j \gt= 1)$
Let L be context free
Therefore, by Pumping Lemma
| y | > 0, | xy | <= p
Where p is an integer such that | s | >= p
Let $y = 1^j \ and \ x = 0^i \ and \ z = 2^i3^j$
Therefore, | x | = i,| xy | = i + j and | z | = i + j
But | xy | >= p
Hence, there arise two cases
Case 1: If | xy |= p then
i + j = p
ifi = 0, j = p ….………….(1)
Case 2: If | xy |< p
i + j < p
If i = 0,then j < p
Hence, a tentative value for p can only be found if i = 0, not for other values of I as we would not understand whether it would take case 1 or case 2.
ii) $L = {SS^T | S Σ (a,b)*}$
We assume a value for L such as
L = bbabaababb
Let x = bbab, y = aa and z = babb
Therefore, | x | = 4,| y | = 2 and | z | = 4
Therefore, by Pumping Lemma, there exists a ‘p’ such that
| y | > 0 and | xy | <= p
But | xy | = 2 + 4 = 6(in this example)
| xy | = X + 2 (in general) ……………………(1)
Hence, two cases arise out
Case 1: | xy | = p
Therefore, p = 6
Case 2: | xy | < p
Therefore, p > 6
So in general, value of p would depend on number of occurrences the x-part of the string
Hence, the language can be generated by a context free grammar without needing to worry about the value for p.
Hence, the language maybe be context free or some other type of language.