3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2026-07-30 02:33:51 +00:00
z3/examples/python
Guangyu (Gary) HU 704dc9375d
mini_ic3: fix generalize() returning empty/init-overlapping core (#9245)
Two fixes in examples/python/mini_ic3.py:

1. generalize(): the polarity of the disjointness check was inverted,
   and there was no guard against an empty unsat core. With an empty
   core, And([])=True so check_disjoint(init, prev(True)) is always
   False (init is sat), and the code returned the empty core. That
   empty core then became cube2clause([])=Or([])=False, which got
   added as a lemma to all frames. The frame became inconsistent and
   is_valid() returned And(Or())=False as the "inductive invariant".

   Fix: require len(core) > 0 AND check_disjoint(init, prev(core))
   (without the spurious 'not'), so the core is only used when it
   is genuinely disjoint from init.

2. is_transition(): when an init rule's body happens to be an And
   without any Invariant predicate (e.g. (and (not A) (not B) ...)),
   is_body() returns (And(...), None). is_transition then passed
   inv0=None to subst_vars() which crashed inside get_vars(). Add an
   explicit None check so the rule falls through to is_init().

Verified on horn1..5 (unchanged behavior), h_CRC and h_FIFO from the
blocksys benchmarks (now correctly return CEX matching z3 spacer),
and cache_coherence_three (no longer collapses to (and or)).
2026-04-09 02:01:07 -07:00
..
bounded model checking three smt2 examples added and one python example updated (#5690) 2021-12-01 16:21:12 -08:00
complex
data
hamiltonian
mus marco: immediately shrink to core if not subset (#5203) 2021-04-20 12:29:52 -07:00
tutorial use structured proof hints 2022-05-28 09:37:41 -07:00
all_interval_series.py
bincover.py Add branch and bound solver, for fun 2023-12-23 11:58:29 -08:00
CMakeLists.txt
efsmt.py handle return status 2022-04-04 20:19:15 +02:00
example.py
hs.py updated experiment 2021-03-26 14:58:23 -07:00
mini_ic3.py mini_ic3: fix generalize() returning empty/init-overlapping core (#9245) 2026-04-09 02:01:07 -07:00
mini_quip.py
parallel.py
prooflogs.py add example for monitoring proof logs 2022-10-19 13:37:51 -07:00
proofreplay.py Fix some typos. (#7115) 2024-02-07 23:06:43 -08:00
rc2.py fix #5080 assertion is violated on legal input, add an example 2021-03-05 15:01:39 -08:00
README
simplify_formula.py formula simplification example 2022-08-11 09:33:36 +03:00
socrates.py
trafficjam.py
union_sort.py
visitor.py add example for #5933 2022-04-05 04:26:40 +02:00

The example is copied to the build directory during configuration.
You can execute it using
    python example.py
in the build directory after you build Z3.