A more thorough explanation:

Definition: A type of will that is also known as a mystic will. It is a secret will that is signed by the testator and sealed by a notary in the presence of witnesses. The notary then writes down all the details of the transaction on the envelope containing the will.

Example: John wants to leave his estate to his secret lover, but he doesn't want his family to know. He creates a mystic testament, signs it, and seals it in an envelope in the presence of a notary and witnesses. The notary writes down all the details of the transaction on the envelope, and John keeps the envelope in a safe place.

Explanation: The example illustrates how a mystic testament works. It is a secret will that is signed by the testator and sealed by a notary in the presence of witnesses. The notary writes down all the details of the transaction on the envelope containing the will. This type of will is used when the testator wants to keep their wishes a secret from their family or other beneficiaries.