Demonstrates uninterpreted sorts and how all-sat behaves for them. Thanks to Eric Seidel for the idea.
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.
An uninterpreted classify function. Really, we only care about the fact that such a function exists, not what it does.
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:
genLsSolution #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.