Agda formalization of Intuitionistic Propositional Logic (IPL)
Normalization by Evaluation for IPL (without soundness)
The simple Normalization by Evaluation (NbE) algorithm that produces from every IPL derivation a normal derivation.
Version presented 2018-07-19 at the Initial Types Club:
Soundness of NbE means that the computational behavior (functional interpretation) of IPL proofs is preserved by normalization.
We implement sound-by-construction NbE using Kripke predicates.