Tuned wf_iff_no_infinite_down_chain proof, based on Konrads ideas.
Added selectI2EX.
(* Title: HOL/Modelcheck/ROOT.ML ID: $Id$ Author: Olaf Mueller, Jan Philipps, Robert Sandner Copyright 1997 TU MuenchenThis is the ROOT file for the Eindhoven Modelchecker example*)use_thy"Example";