init README

Model E1337 - Rolling Code Lock/README.md

@@ -61,7 +61,7 @@ Predicting the output of ```next(26)``` is equivalent to predicting the output o
 
 My approach to predict the ```getrandbit``` is to use the output of a few ```next(26)``` to recover as much of ```state``` as needed to be able to predict the next bits. An observation is that the output of ```getrandbit``` is can be represented as a series of XOR of the bits of the original state (from ```setup(seed)```).
 
-Define the original state as a list of sets. ```state_a = [{63}, {62}, {61}, {60}...{0}]```. The numbers represent the index of the bit of the state, ```63``` being the ```MSB``` and ```0``` being the ```LSB```. As ```state_a``` gets put through ```getrandbit```, it will evolve. E.g. ```state_a = [{0}, {63, 61}...]```. The nth set in ```state_a``` represents the nth bit of ```state_a``` as a sequence of XORs of the bits of the original state. E.g. if ```state_a[2] = {63, 61}```, then ```state & 2**2 = a63 ^ a61```, where the original state has bits ```a63, a62, a61..., a0```.
+Define the original state as a list of sets. ```state_a = [{63}, {62}, {61}, {60}...{0}]```. The numbers represent the index of the bit of the state, ```63``` being the ```MSB``` and ```0``` being the ```LSB```. As ```state_a``` gets put through ```getrandbit```, it will evolve. E.g. ```state_a = [{0}, {63, 61}...]```. The nth set in ```state_a``` represents the nth bit of ```state_a``` as a sequence of XORs of the bits of the original state. E.g. if ```state_a[-5] = {63, 61}```, then ```state & 2**4 = a63 ^ a61```, where the original state has bits ```a63, a62, a61..., a0```.
 
 A function ```getrandbit_track(state_a)``` would evolve ```state_a``` upon passing through ```getrandbit```. My implementation as follows. Do note that I reserved index ```64``` to represent ```1```, while all the other index represents the nth bit of the original state: