{- |

Module : $Header$

Description : a simple proof tree

Copyright : (c) DFKI GmbH, Uni Bremen 2002-2008

License : similar to LGPL, see HetCATS/LICENSE.txt or LIZENZ.txt

Maintainer : Christian.Maeder@dfki.de

Stability : provisional

Portability : portable

Datatype for storing of the proof tree

-}

module Common.ProofTree where

{- |

Datatype for storing of the proof tree. The Show class is instantiated.

-}

data ProofTree = ProofTree String deriving (Eq, Ord)

instance Show ProofTree where

show (ProofTree st) = st

emptyProofTree :: ProofTree

emptyProofTree = ProofTree ""