It is pretty hard for me to understand, how binary representation of number may be context free. This language $L=\{bin(n)bin(n+1)^R : n \geq 0\}$ is context free.
Here, at 1.b, is a PDA which describes this language, so it is context free. I've tried to construct a context free grammar for this one, but I have no idea when to even start. How can I express a CFG binary representation of a number? I would be very glad for any suggestions.