for any string w = w1w2 · · · wn, the reverse of w, written wr, is the string w in reverse order, wn · · · w2w1. for any language a, let ar = {wr| w ∈ a}. show that if a is regular, so is a

for any string w = w1w2 · · · wn, the reverse of w, written wr, is the string w in reverse order, wn · · · w2w1. for any language a, let ar = {wr| w ∈ a}. show that if a is regular, so is a