277c685b1429c51f92b006f38aca4b89e0f4f2fdChristian Maeder{-# OPTIONS -fallow-undecidable-instances #-}

277c685b1429c51f92b006f38aca4b89e0f4f2fdChristian Maeder{- |

277c685b1429c51f92b006f38aca4b89e0f4f2fdChristian MaederModule : $Header$

277c685b1429c51f92b006f38aca4b89e0f4f2fdChristian MaederDescription : Instance of class Logic for propositional logic

277c685b1429c51f92b006f38aca4b89e0f4f2fdChristian MaederCopyright : (c) Dominik Luecke, Uni Bremen 2007

277c685b1429c51f92b006f38aca4b89e0f4f2fdChristian MaederLicense : similar to LGPL, see HetCATS/LICENSE.txt or LIZENZ.txt

277c685b1429c51f92b006f38aca4b89e0f4f2fdChristian Maeder

8cd8515a95c02d0701aa8a52d3dba93b96b8f875Christian MaederMaintainer : luecke@tzi.de

8191ab400cc9ebb5a3f6c6f18104a208aae187e8Christian MaederStability : experimental

2a776f7803cf5250668849ab0af9d378dfefd2f3Christian MaederPortability : portable

8cd8515a95c02d0701aa8a52d3dba93b96b8f875Christian Maeder

8cd8515a95c02d0701aa8a52d3dba93b96b8f875Christian MaederDefinition of morphisms for propositional logic

2a776f7803cf5250668849ab0af9d378dfefd2f3Christian Maeder-}

8cd8515a95c02d0701aa8a52d3dba93b96b8f875Christian Maeder

8cd8515a95c02d0701aa8a52d3dba93b96b8f875Christian Maedermodule Propositional.Morphism where

8cd8515a95c02d0701aa8a52d3dba93b96b8f875Christian Maeder

dda27ed86257e0480f862b841259819f59d4724ecmaederimport qualified Common.InjMap as InjMap

dda27ed86257e0480f862b841259819f59d4724ecmaederimport qualified Common.Lib.Set as Set

dda27ed86257e0480f862b841259819f59d4724ecmaederimport Propositional.Sign as Sign

e938e50e25d4a2365fab789af709590d3d6ce89dcmaederimport Common.Id

516ca24f64f1b6e45577ee44dced94e7e358336bChristian Maeder

8191ab400cc9ebb5a3f6c6f18104a208aae187e8Christian Maedertype PropMap = InjMap.InjMap Id Id

277c685b1429c51f92b006f38aca4b89e0f4f2fdChristian Maeder

data Morphism = Morphism

{

source :: Sign

, target :: Sign

, propMap :: PropMap

} deriving (Eq, Show)

idMor :: Sign -> Morphism

idMor a = Morphism

{ source = a

, target = a

, propMap = makeIdMor $ items a

}

makeIdMor :: (Ord a) => Set.Set a -> InjMap.InjMap a a

makeIdMor a = Set.fold (\x -> InjMap.insert x x) InjMap.empty a