ℶ

ℶ (English symbol name beth)

1. (set theory) Symbol for the cardinality of an infinite set in a iterative hierarchy of power sets, starting with ℵ₀. Usually indexed by an ordinal number.

   ${\displaystyle \beth _{0}=\aleph _{0}}$ , ${\displaystyle \beth _{\alpha +1}=2^{\beth _{\alpha }},}$ and ${\displaystyle \beth _{\lambda }=\sup\{\beth _{\alpha }:\alpha <\lambda \}}$ for a limit ordinal λ.

Unicode has two code points for the Hebrew letter beth. For Hebrew text, ב should be used. This character should be used for the mathematical symbol since it retains the left-to-right orientation of the text.

• Beth number on Wikipedia.Wikipedia
• ℵ