What is the required 'iddah' period if a woman delivers a child less than six months after a second intercourse and more than four years after separation from the first relationship?

Primary text

If a woman gives birth less than six months after the second intercourse and more than four years after separation from the first man, the child is not attributed to either of them, and her 'iddah' for neither relationship concludes upon delivery. This is because it is known that the child is from a third, intervening intercourse. Therefore, her 'iddah' for that intervening intercourse concludes upon delivery, and she must then complete the remainder of the 'iddah' for the first man and begin a new 'iddah' for the second man, as a third occasion necessitating an 'iddah' has occurred.