One-breather Eq. (12) with t = 0, α = − 1 / 2 , a 1 = − 1 , b 1 = 1 / 2 , c 1 = 1 / 5 , d 1 = 2 / 3 , η 1 0 = η 2 0 = 0 . (a) v b [ 1 ] , (b) r b [ 1 ] .