Paul Giaccone wrote:
There is a very good reason why the "rule" (actually a relation) is absent in mathematics: namely that it cannot be defined in a meaningful, useful way, as others have already demonstrated. If it can't be done meaningfully in mathematics, it can't be done meaningfully in computer science either.
That's not true. An ordering cannot be defined for the mathematical construct "complex number" that is meaningful and useful to mathematicians. That doesn't mean that the same applies to computer scientists - it is very well possible to define an operator < for std::complex that is useful (allows using the class itself, as well as tuples containing it, to be easily used in sorted containers) and meaningful (it's lexicographical - it certainly has meaning, even if that meaning doesn't make sense to mathematicians). Sebastian Redl