[kiujygtyujik]

Thats the difference between maths and engineering.

A proof that has a single exception is wrong, a brige that stays up with a broken rivet is correct

[sqrt17]

A bridge that depends on all rivets being perfect is a bad thing. A proof that no longer holds outside of its domain of application is still useful.

The trick is to recognize when you need one and when you'd rather use the other.

[kiujygtyujik]

Same in software - an application that fills a business purpose but has bugs or "errors" is correct.

An error free perfect piece of software hat doesn't is useless

[Twisol]

> A proof that has a single exception is wrong, a brige that stays up with a broken rivet is correct

I really like how the mathematical part of that phrase is literal, and the programming part is metaphorical.