Fixed problem with batch mode layout, which caused an AWT exception when
no X11 connection was available.
(* Title: HOLCF/IOA/meta_theory/IOA.thy ID: $Id$ Author: Olaf Mueller Copyright 1996,1997 TU MuenchenThe theory of I/O automata in HOLCF.*) IOA = SimCorrectness + Compositionality + Deadlock