Alternative set theory

From Exampleproblems

Generically, an alternative set theory is an alternative mathematical approach to the concept of set. It is a proposed alternative to standard set theory.

Some of the alternative set theories are:

• the theory of semisets;
• rough set theory;
• fuzzy set theory.

Specifically, Alternative Set Theory (or AST) refers to a particular set theory developed in the 1970s and 1980s by Petr Vopěnka and his students. It builds on some ideas of the theory of semisets, but also introduces more radical changes: for example, all sets are finite in AST.

See also

• Non-well-founded set theory

References

• Vopěnka, P. Mathematics in the Alternative Set Theory. Leipzig: Teubner, 1979.