Meh, it's the age old distinction between Formal vs Informal language.

Simply put: Formal language = No ambiguities.

Once you remove all ambiguous information from an informal spec, that, whatever remains, automatically becomes a formal description.

Is that true though? If I define a category or range in formal language, I’m still ambiguous on the exact value. Dealing with randomness is even worse (eg input in random order), and can’t be prevented in real world programs.