[TYPES] Implementations using explicit substitutions

[Carsten Schuermann]

Dear colleagues,

We are currently writing a paper on explicit substitution calculi, and we
would like to include references to implementations of proof
assistants, theorem provers, and programming languages that use them.  

If you are aware of any such system please send us an email. 

Best regards,
-- Anders Schack-Nielsen and Carsten Schuermann