entailed

Having or resulting from a legal entail; pertaining to inheritance that is limited in descent to a particular class of issue.

The role, therefore, which prevented the alienation of entailed estates being thus broken in upon, fines and recoveries became the common modes of assurance in conveying that species of property.

Entailed property must be considered by every one who knows thoroughly what society is, as anti-social. It has been set apart by selfish men for the sole benefit of their favoirite heirs, in order that they might be though its instrumentality enabled to live anti-socially, and to be excempt from the usual operation of the laws which take cognizance of other individuals when they contract debt.

That is required logically (by something); That has logical dependencies.

Needless to say, the unexplained emergent phenomenon (and the entailed system whose functions can explain it) or the not-yet-existing artifact (and the system required for its construction) can itself be anything from a very simple to a very complex entity.

The relation of Keeper is an entailed role of pet dog, inasmuch as every pet dog has someone who is its keeper.