1. ∑* - (wwr)
wwr ={∊,aa,bb,abba,abbbba..............}
then ∑* - (wwr) = {a,b,aba,ab,ba,................}
wwr is Regular. Complement of regular is regular
2.∑* - (wxwr)
wxwr=(aaa,aba,abba..........)
then ∑* - (wxwr) = {a,b,aa,bb...................}
wxwr is DCFL . DCFL closed under complement. ∑* - (wxwr) is DCFL
3.∑* - (ww)
ww=(aa,bb,abab............)
∑* - (ww)=(a,b,abba,abaa.............)
ww is CSL. Complement of CSL can be CSL
4.∑* - (wxw)
wxw=(aaa,aba,abaab............)
∑* - (wxw)=(a,b,aa,ab......................)
wxw is CSL. Complement of CSL is also CSL,