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Monthly Downloads: 34
Programming language: Haskell
License: BSD 3-clause "New" or "Revised" License
Tags: Math     Data     Logic     Expressions    
Latest version: v0.4
Add another 'expressions' Package

README

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Usage

λ> :set -XDataKinds -XFlexibleContexts -XKindSignatures -XRankNTypes -XTypeInType -XTypeOperators
λ> :m Data.Expression Data.Expression.Z3 Data.Singletons
λ> import Z3.Monad hiding (assert)

Encode expression in Z3 AST

λ> :{
let x, y :: forall f. VarF :<: f => IFix f 'IntegralSort
    x = var "x"
    y = var "y"
:}
λ> evalZ3 $ astToString =<< toZ3 (forall [x] (exists [y] (x .+. y .=. cnst 0)) :: Lia 'BooleanSort)
(forall ((x Int)) (exists ((y Int)) (= (+ x y) 0)))

Decode expression from Z3 AST

λ> :{
evalZ3 $ do
  x  <- mkIntVar =<< mkStringSymbol "x"
  x' <- toApp x
  y  <- mkIntVar =<< mkStringSymbol "y"
  y' <- toApp y
  z  <- mkInt 0 =<< mkIntSort
  fromZ3 =<< mkForallConst [] [x']
         =<< mkExistsConst [] [y']
         =<< mkEq z
         =<< mkAdd [x, y] :: Z3 (Lia 'BooleanSort)
:}
(forall ((x : int)) (exists ((y : int)) (= 0 (+ (x : int) (y : int)))))

Z3 API

λ> :{
evalZ3 $ do
  let x', y' :: forall f. VarF :<: f => IFix f 'IntegralSort
      x' = var "x"
      y' = var "y"

      x, y :: Lia 'IntegralSort
      x = x'
      y = y'

  m <- local $ do
    assert (x .=. cnst 42)
    model x

  uc <- unsatcore [ x .=. cnst 2, x .=. cnst 1, y .=. cnst 2, x ./=. y ]

  i <- interpolate [ x .=. cnst 2, x .=. y, y .=. cnst 4 ]

  e <- eliminate $ forall [x'] (x .=. cnst 2)

  return (m, uc, i, e)
:}
(42,[(= (x : int) 2),(= (x : int) 1)],[(= (x : int) 2),(not (= (y : int) 4))],false)