sbv-8.4: SMT Based Verification: Symbolic Haskell theorem prover using SMT solving.

Copyright(c) Levent Erkok
LicenseBSD3
Maintainererkokl@gmail.com
Stabilityexperimental
Safe HaskellNone
LanguageHaskell2010

Documentation.SBV.Examples.ProofTools.Sum

Contents

Description

Example inductive proof to show partial correctness of the traditional for-loop sum algorithm:

    s = 0
    i = 0
    while i <= n:
       s += i
       i++

We prove the loop invariant and establish partial correctness that s is the sum of all numbers up to and including n upon termination.

Synopsis

System state

data S a Source #

System state. We simply have two components, parameterized over the type so we can put in both concrete and symbolic values.

Constructors

S 

Fields

  • s :: a
     
  • i :: a
     
  • n :: a
     
Instances
Functor S Source # 
Instance details

Defined in Documentation.SBV.Examples.ProofTools.Sum

Methods

fmap :: (a -> b) -> S a -> S b #

(<$) :: a -> S b -> S a #

Foldable S Source # 
Instance details

Defined in Documentation.SBV.Examples.ProofTools.Sum

Methods

fold :: Monoid m => S m -> m #

foldMap :: Monoid m => (a -> m) -> S a -> m #

foldr :: (a -> b -> b) -> b -> S a -> b #

foldr' :: (a -> b -> b) -> b -> S a -> b #

foldl :: (b -> a -> b) -> b -> S a -> b #

foldl' :: (b -> a -> b) -> b -> S a -> b #

foldr1 :: (a -> a -> a) -> S a -> a #

foldl1 :: (a -> a -> a) -> S a -> a #

toList :: S a -> [a] #

null :: S a -> Bool #

length :: S a -> Int #

elem :: Eq a => a -> S a -> Bool #

maximum :: Ord a => S a -> a #

minimum :: Ord a => S a -> a #

sum :: Num a => S a -> a #

product :: Num a => S a -> a #

Traversable S Source # 
Instance details

Defined in Documentation.SBV.Examples.ProofTools.Sum

Methods

traverse :: Applicative f => (a -> f b) -> S a -> f (S b) #

sequenceA :: Applicative f => S (f a) -> f (S a) #

mapM :: Monad m => (a -> m b) -> S a -> m (S b) #

sequence :: Monad m => S (m a) -> m (S a) #

Fresh IO (S SInteger) Source #

Fresh instance for our state

Instance details

Defined in Documentation.SBV.Examples.ProofTools.Sum

Show a => Show (S a) Source # 
Instance details

Defined in Documentation.SBV.Examples.ProofTools.Sum

Methods

showsPrec :: Int -> S a -> ShowS #

show :: S a -> String #

showList :: [S a] -> ShowS #

Generic (S a) Source # 
Instance details

Defined in Documentation.SBV.Examples.ProofTools.Sum

Associated Types

type Rep (S a) :: Type -> Type #

Methods

from :: S a -> Rep (S a) x #

to :: Rep (S a) x -> S a #

Mergeable a => Mergeable (S a) Source # 
Instance details

Defined in Documentation.SBV.Examples.ProofTools.Sum

Methods

symbolicMerge :: Bool -> SBool -> S a -> S a -> S a Source #

select :: (Ord b, SymVal b, Num b) => [S a] -> S a -> SBV b -> S a Source #

type Rep (S a) Source # 
Instance details

Defined in Documentation.SBV.Examples.ProofTools.Sum

type Rep (S a) = D1 (MetaData "S" "Documentation.SBV.Examples.ProofTools.Sum" "sbv-8.4-LKcvIZGSCFCGr6QyM4W6l5" False) (C1 (MetaCons "S" PrefixI True) (S1 (MetaSel (Just "s") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 a) :*: (S1 (MetaSel (Just "i") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 a) :*: S1 (MetaSel (Just "n") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 a))))

sumCorrect :: IO (InductionResult (S Integer)) Source #

Encoding partial correctness of the sum algorithm. We have:

>>> sumCorrect
Q.E.D.