  We describe a natural deduction formalization of intuitionistic and classical
propositional logic in the Isabelle/Pure framework. In contrast to earlier
work, where we explored the pedagogical benefits of using a deep embedding
approach to logical modelling, here we employ a logical framework modelling.
This gives rise to simple and natural teaching examples and we report on the
role it played in teaching our Automated Reasoning course in 2020 and 2021.
