Data.Logic.Classes.Constants

Documentation

class Constants p where

Some types in the Logic class heirarchy need to have True and False elements.

Methods

asBool :: p -> Maybe Bool

fromBool :: Bool -> p

Instances

Constants String

This is probably dangerous.

Constants FOL

Constants PredName

Constants FOLEQ

Constants (PropForm formula)

Constants (Formula atom)

Constants (Formula a)

Constants (Formula a)

Constants p => Constants (Predicate p (PTerm v f))

(Constants p, Eq (NormalSentence v p f)) => Constants (NormalSentence v p f)

(Constants p, Eq (Sentence v p f)) => Constants (Sentence v p f)

Constants p => Constants (Formula v p f)

(Constants (Formula v p f), Predicate p, Variable v, Function f v) => Constants (Formula v p f)

ifElse :: a -> a -> Bool -> a

true :: Constants p => p

(⊨) :: Constants formula => formula

false :: Constants p => p

(⊭) :: Constants formula => formula

prettyBool :: Bool -> Doc