Code (set theory)

In set theory, a code for a set x is a set E $\subset$ ω×ω such that there is an isomorphism between (ω,E) and (X,$\in$) where X is the transitive closure of {x}.

See also

• Hereditarily countable set

References

• William J. Mitchell,"The Complexity of the Core Model","Journal of Symbolic Logic",Vol.63,No.4,December 1998.