Hereditarily countable set

In set theory, a set is called hereditarily countable if it is a countable set of hereditarily countable sets. This inductive definition is in fact well-founded and can be expressed in the language of first-order set theory. A set is hereditarily countable if and only if it is countable, and every element of its transitive closure is countable. If the axiom of countable choice holds, then a set is hereditarily countable if and only if its transitive closure is countable.

单词	Hereditarily countable
释义	Hereditarily countable 英语百科 Hereditarily countable set In set theory, a set is called hereditarily countable if it is a countable set of hereditarily countable sets. This inductive definition is in fact well-founded and can be expressed in the language of first-order set theory. A set is hereditarily countable if and only if it is countable, and every element of its transitive closure is countable. If the axiom of countable choice holds, then a set is hereditarily countable if and only if its transitive closure is countable.
随便看	lacchesse的意思 laccic的意思 laccic acid的意思 laccifer的意思 Lacciferidae的意思 Lacciferinae的意思 Laccifer lacca的意思 Laccifer lacca Kerr.的意思 laccifer lacca parasite的意思 laccijaaric ester的意思 laccijalaric acid的意思 laccin的意思 laccishellolic acid的意思 laccnic acid的意思 laccol的意思 laccolite的意思 laccolite的意思 laccolith的意思 laccolith的意思 laccolithic dome的意思 laccolithic mountain的意思 laccolithic sill的意思 laccolith, laccolite的意思 laccolith mountain的意思 laccolith的意思