Is a husband's statement to his wife, "You are divorced," with the intention of a single divorce, followed by "and this divorce is irrevocable," meaning he will not go back on this divorce, considered a single divorce?

Describing a divorce as irrevocable does not prevent it from being revocable according to the Maliki, Hanafi, and Shafi'i schools, provided that the wife has been consummated with. However, the Hanbalis are of the opinion that explicitly describing an unequivocal divorce with a negation of revocability renders it a triple divorce.