Noblemen who held lands hereditarily passed those lands on within their family. Noblemen who held lands (fiefdoms) hereditarily passed those lands on within their family. The hereditarily finite sets are a subclass of the Von Neumann universe. They were vassals who ruled, mostly hereditarily, over their respective territories. Another example is the set of hereditarily countable sets. The smallest example of an admissible set is the set of hereditarily finite sets. It is formula 32, the class of hereditarily finite sets, with the inherited membership relation. V is also symbolized by formula 2, meaning hereditarily of cardinality less than formula 3. The set of all well-founded hereditarily finite sets is denoted "V". In fact, the superstructure over {} consists of all of the hereditarily finite sets. From 1934, forced sterilisation of the hereditarily diseased had commenced in Germany. The permutation model consists of all hereditarily symmetric elements, and is a model of ZFA. A logic is called hereditarily structurally complete, if any extension is structurally complete. The order topology induced by a total order may be shown to be hereditarily normal. For this purpose persons were appointed to whom rentfree lands were hereditarily assigned.