sbv-5.6: SMT Based Verification: Symbolic Haskell theorem prover using SMT solving.

Copyright(c) Levent Erkok
Safe HaskellNone



Demonstrates uninterpreted sorts and how all-sat behaves for them. Thanks to Eric Seidel for the idea.



data L Source

A "list-like" data type, but one we plan to uninterpret at the SMT level. The actual shape is really immaterial for us, but could be used as a proxy to generate test cases or explore data-space in some other part of a program. Note that we neither rely on the shape of this data, nor need the actual constructors.


Cons Int L 


Eq L Source 
Data L Source 
Ord L Source 
Read L Source 
Show L Source 
HasKind L Source

Similarly, HasKinds default implementation is sufficient.

SymWord L Source

Declare instances to make L a usable uninterpreted sort. First we need the SymWord instance, with the default definition sufficing.

classify :: SBV L -> SInteger Source

An uninterpreted "classify" function. Really, we only care about the fact that such a function exists, not what it does.

genLs :: IO AllSatResult Source

Formulate a query that essentially asserts a cardinality constraint on the uninterpreted sort L. The goal is to say there are precisely 3 such things, as it might be the case. We manage this by declaring four elements, and asserting that for a free variable of this sort, the shape of the data matches one of these three instances. That is, we assert that all the instances of the data L can be classified into 3 equivalence classes. Then, allSat returns all the possible instances, which of course are all uninterpreted.

As expected, we have:

>>> genLs
Solution #1:
  l  = L!val!0 :: L
  l0 = L!val!0 :: L
  l1 = L!val!1 :: L
  l2 = L!val!2 :: L
Solution #2:
  l  = L!val!2 :: L
  l0 = L!val!0 :: L
  l1 = L!val!1 :: L
  l2 = L!val!2 :: L
Solution #3:
  l  = L!val!1 :: L
  l0 = L!val!0 :: L
  l1 = L!val!1 :: L
  l2 = L!val!2 :: L
Found 3 different solutions.