Simplify the following text for a Grade 10 native English-speaking person.
Original: One of the difficult ones is that the punishment can not be enforced unless there is a confession of the person , or four male eyewitnesses who each saw , simultaneously , the penis of the man inside the vulva of the woman .
Simplified: One of the difficult ones is that the punishment can not be enforced unless there is a confession of the person , or four male eyewitnesses who each saw the act being committed .