For questions about the surreal numbers, which are formed by extending the ordered field of real numbers with infinitely large and infinitely small numbers.

For questions about the surreal numbers, which are a real-closed ordered proper-class-sized field that contains both the real numbers and the ordinal numbers. Thus they contain both infinite numbers (including the ordinals, but also infinite numbers like ω-1 and sqrt(ω)) and infinitesimal numbers (like 1/ω). They can also be identified with a subclass of two-player partisan games.

For questions about the surreal numbers, which are formed by extending the ordered field of real numbers with infinitely large and infinitely small numbers.