Surreal games[1] are probably my favorite example. But any partially-ordered set without total order can be an example. [1] https://en.wikipedia.org/wiki/Surre

Surreal games[1] are probably my favorite example. But any partially-ordered set without total order can be an example. [1] https://en.wikipedia.org/wiki/Surreal_number#Games https://en.wikipedia.org/wiki/Surreal_number#Games