Mathematicians (and those in related sciences) very frequently speak of whether a mathematical object — a number, a function, a set, a space of one sort or another — is "well-behaved" or not. While the term has no fixed formal definition, it can have fairly precise meaning within a given context. In pure mathematics, "well-behaved" objects are those that can be proved or analyzed by elegant means to have elegant properties. In both pure and applied mathematics (optimization, numerica… (More on Well-behaved)