A more thorough explanation:

QUARTA FALCIDIANA

Quarta Falcidiana is a Latin term that refers to the one-fourth part of an estate that one or more instituted heirs are entitled to retain under Roman law. It is also known as Falcidian portion. For example, if a person dies and leaves behind an estate worth $100,000, the instituted heir(s) can retain $25,000 as their quarta Falcidiana.

This concept is related to forced heir and legitime, which are legal terms used to describe the rights of heirs to inherit a portion of the estate of a deceased person. Quarta Falcidiana is different from Quarta Trebellianica, which is another legal term used in Roman law to describe the one-third part of an estate that a testator could bequeath to a person of their choice.

John's father passed away and left behind an estate worth $500,000. John was the instituted heir and was entitled to retain one-fourth of the estate as his quarta Falcidiana. Therefore, John could keep $125,000 of his father's estate, and the remaining $375,000 would be distributed among the other heirs according to the law.

This example illustrates how the concept of quarta Falcidiana works in practice. It shows that the instituted heir(s) have the right to retain a portion of the estate, which is determined by law, and the rest of the estate is distributed among the other heirs according to the rules of inheritance.