How would you define the 2-SAT complement pseudo code?

The information I gathered is, Let x be random variable chosen then we have to check if there exist a path between x to ~x and from ~x to x. If such a path does not exist then it is 2-sat complement

I am not sure if it is correct or not. I don’t even understand the explanation.

How would you define the pseudo code? What would be its correctness?