What is the ruling on the wife now, and has she become irrevocably separated from her husband, who divorced her twice during menstruation, of which he was unaware, and once during a period of purity in which he had intercourse with her, believing that divorce during menstruation did not count, then he learned that it did?

The majority of scholars hold that divorce pronounced during menstruation or during a period of purity in which sexual intercourse has occurred, is valid, though the one who pronounces it is sinful. If a person is qualified to weigh and examine evidence, and previously inclined towards the view that divorce pronounced during menstruation or after sexual intercourse does not take effect, and acted upon that, but later inclined towards the view that it does take effect, then he should act upon his most recent inclination in the future. He should not invalidate his previous inclination and ijtihad (independent reasoning), unless he changed his first inclination before acting upon it; in that case, he should act upon his second inclination. For one ijtihad is not invalidated by another similar ijtihad. However, if he is not qualified for ijtihad, he must consult scholars and act according to their opinion. We advise referring to Sharia courts, as a judge's ruling resolves disagreements.