README.md

nano-smt

NanoSMT is a "toy" SMT Solver for educational purposes.

NanoSMT will combine a basic

1. Propositional Logic (DPLL)

with a Nelson-Oppen combination of theory solvers for

2. Equality & Uninterpreted Functions (Congruence Closure)
3. Difference Constraints (Bellman-Ford)

Over time, we may add:

• Fancy SAT heuristics like non-chronological backtrack, etc.
• Linear Arithmetic via Simplex.

TODO

• Write SAT solver

• Test SAT solver

• Write EQ solver

  • Write UnionFind
  • Write HashCons [see undefined in NelsonOppen] <--------- HEREHEREHEREHERE

• Test EQ solver

• Write NO = SAT + EQ

• Test NO solver

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• Add UIF/CC to EQ solver
• Test EUF
• Test SAT+EUF
• Write DIFF solver
• Test DIFF solver
• Test SAT+EUF+DIFF

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{-# LANGUAGE ExistentialQuantification #-} {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE UndecidableInstances #-}

module Foo where

class Foo a where zz :: a -> String

data Obj = forall a. (Foo a) => Obj a

instance Show a => Foo a where zz = show

xs :: [Obj] xs = [Obj 1, Obj "foo", Obj 'c']

doShow :: [Obj] -> String doShow [] = "" doShow ((Obj x):xs) = zz x ++ doShow xs

bob :: [Obj] -> [String] bob xs = map ((Obj x) -> zz x) xs