Portal for research and teaching in higher-order logic, in particular using the proof assistant Isabelle for formalization and verification.
Getting Started with Isabelle
IsaFoL: Isabelle Formalization of Logic
Proof Assistants and Related Tools - The PART Project
NaDeA: A Natural Deduction Assistant with a Formalization in Isabelle
Jørgen Villadsen 2017-11-12 http://hol.compute.dtu.dk/