Craft externalizes nothing and transfers by apprenticeship. Engineering writes the governing relation down where someone else can find it wrong.
Four times now I have written the same three sentences in different notations, for four problems
that looked unrelated: a design method, a coding technology, an architecture-derivation procedure,
and a contract-modelling tool. I noticed the repetition only after the fourth. Here it is, stated
as precisely as I can manage.






