content: {- |
  Module      :  $Id$
  Description :  modal logic extension of CASL
  Copyright   :  (c) Christian Maeder and Uni Bremen 2006
  License     :  GPLv2 or higher, see LICENSE.txt
  
  Maintainer  :  Christian.Maeder@dfki.de
  Stability   :  provisional
  Portability :  portable (except Modal.Logic_Modal)
  
  This folder contains the files for ModalCASL basic specs
  
  ModalCASL is the modal logic extension of CASL.  See
  /Heterogeneous specification and the heterogeneous tool set/
  (<http://www.informatik.uni-bremen.de/~till/papers/habil.ps>), section 3.2.
  
  The modules for ModalCASL largely are built on top of those for "CASL",
  using the holes for future extensions that have been left in the
  datatypes for CASL.
  
  * "Modal.AS_Modal"     abstract syntax
  
  * "Modal.Parse_AS"     parser
  
  * "Modal.Print_AS"     pretty printing
  
  * "Modal.ModalSign"    signatures
  
  * "Modal.StatAna"      static analysis
  
  * "Modal.ModalSystems" recognition of various systems such as S4, S5 etc.
  
  * "Modal.ATC_Modal"    ATerm conversion
  
  * "Modal.Logic_Modal"  the ModalCASL instance of type class 'Logic.Logic.Logic'
  
  -}
  module Modal where
  