Given a string w=w 1
 
 w 2
 
 …w n
 
 , the reverse of w, is w R
 = language L is L R
 ={w R
 ∣w∈L}. Prove that the class of reversal. 4. Σ 3
 
 = ⎩
 ⎨
 ⎧
 
 ⎣
 ⎡
 
 0
 0
 0
 
 ⎦
 ⎤
 
 , ⎣
 ⎡
 
 0
 0
 1
 
 ⎦
 ⎤
 
 , ⎣
 ⎡
 
 0
 1
 0
 
 ⎦
 ⎤
 
 , ⎣
 ⎡
 
 0
 1
 1
 
 ⎦
 ⎤
 
 , ⎣
 ⎡
 
 1
 0
 0
 
 ⎦
 ⎤
 
 , ⎣
 ⎡
 
 1
 0
 1
 
 ⎦
 ⎤
 
 A string of symbols in Σ 3
 
 gives three rows of 0 s and 1 s, whi