A more thorough explanation:

Definition: Libellary procedure is a legal process that was used in ancient Rome. It refers to the initial steps taken by a plaintiff to start a lawsuit. This involves submitting a written claim, known as a libellus, to a magistrate.

Example: Let's say that a person named John wants to sue his neighbor for damaging his property. John would need to write a libellus, which outlines his claim against his neighbor. He would then submit this document to the magistrate, who would review it and decide whether or not to proceed with the lawsuit.

Explanation: The example illustrates how libellary procedure works in practice. It shows how a plaintiff must take the first step in initiating a lawsuit by submitting a written claim to the magistrate. This is an important part of the legal process, as it allows the magistrate to determine whether or not there is a valid claim to be pursued.