[the_af]

I understand your last point, but my question is:

In order for domain experts to contribute to a formal specification, this specification must be, well, formal, and also serve as a very precise shared language among all domain experts and implementors (i.e. the people who are going to read the spec and build something out of it). Once you go down this road, the specification language becomes as complex as any programming language -- or maybe even more! -- and must be learned by all involved, just like any given programming language. Some people will find it easier to learn, some will struggle or find it bizarrely unfamiliar -- again, just like any given programming language. Any sufficiently expressive specification language will also be subject to the kinds of bugs and complexity that affect programming languages.

So my question is: isn't learning a shared formal specification language more or less as difficult as learning an unfamiliar programming language?