In wxw^r |w,x=(a+b)^+
You can give any string it will start and end with same symbol.
011111000 or if 10000111011 bcz here u have x=(0,1)+ machine will consider only first and last part and remaining as X. since x=(0,1)+.
But if you want apply same concept in ww^r it will not accept all string belonging to that languge.
001110 this is inside ww^r but 01110 is not the inside ww^r so it will not accept all the string belonging to this so this is ww^r |w=(a+b)+ is not regular.