Rules formulated with openVALIDATION are thus at the same time a formal, machine-processable specification, but also a documentation that is easy for people to understand.

Diagramming and documentation costs precious developer time and gets outdated quickly. But not having diagrams or docs ruins productivity and hurts organizational learning. Mermaid addresses this problem by enabling users to create easily modifiable diagrams, it can also be made part of production scripts (and other pieces of code).

I'm maintaining one that can be run and asserted on: https://github.com/cirosantilli/rails-cheat/blob/master/app/test/integration/capybara_test.rb