lambda 3/2 # construction 2A Gallager code with rate 1/3 1x2 I 1/2 at 0/1,0/1 1x1 P 1/1 at 1/2,0/1 1x1 P 1/1 at 1/2,0/1 1x1 P 1/1 at 1/2,0/1