remove the within-filter, replace "at" by "at _ within UNIV" (This allows to remove a couple of redundant lemmas)
(* Title: HOL/SET_Protocol/SET_Protocol.thy
Author: Lawrence C Paulson, Cambridge University Computer Laboratory
Copyright 2003 University of Cambridge
Root file for the SET protocol proofs.
*)
theory SET_Protocol
imports Cardholder_Registration Merchant_Registration Purchase
begin
end