Question

A. Give a grammar for {vv^R | v in Sig+}. (Note: Sig+ = Sig*\{lam}, i.e. the set of non-empty strings over Sig.)

How does this relate to the language in B ?

B. A palindrome over Sig is a word u in Sig* s.t. u^R = u. Let Pal(Sig) be the set of palindromes over Sig.

Answer 1

A. Give a grammar for {vv^R | v in Sig+}. (Note: Sig+ = Sig*\{lam}, i.e. the set of non-empty strings over Sig.)

In this strings will be of form and hence will be in language.

B. A palindrome over Sig is a word u in Sig* s.t. u^R = u. Let Pal(Sig) be the set of palindromes over Sig.

Any string in language of A will be a palindrome.

Proof:

Any string in language would be . Lets take R of this string. = = . Hence proved that all string in langauge in part A will be palindorme. So A will be subset of B.