What are the conditions for the divorce of one under duress not to take effect if the duress was compelling, and does the divorce of one who was coerced into divorcing, and who desired it and intended it in his heart, take effect, given his ignorance of the ruling on the divorce of one under duress, and his knowledge that had it not been for the duress, he would not have divorced?

The divorce of someone under duress (mukrah) does not take effect if the conditions of duress are met. However, if the person under duress intends to effect the divorce, then their divorce takes effect, regardless of whether they knew that the divorce of someone under duress is effective or not. And if a sign of their choice to divorce appears, such as their acting contrary to the duress by divorcing in a manner different from what they were compelled to do, then their divorce takes effect. Consequently, the original intention of the person under duress to divorce makes the duress not a barrier to its occurrence, and ignorance of the details does not prevent the divorce from taking effect.