[agentultra]

Isn't the acronym, test driven development?

All that means to me is that when we start a project we think about what it means for an implementation to be correct and write a test. If we agree on the specification, the test, then a passing implementation means that we have implemented it correctly -- for that particular test.

One of the challenges of using unit tests for this kind of testing is, as you say, difficult with modelling continuous values.

It is also difficult because the "proof" is so small and trivial. You need thousands of examples to gain some confidence... and for even moderately complex software this can not be enough.

Unfortunately, the path to writing good tests and verifying software requires a bit of mathematical vocabulary and reasoning which many developers are too shy to learn or outright hostile towards ("I've never needed no stinking math, this is programming!").

My point is: as long as you're driving the development of your software using testing, I think you're practising TDD.